What does that mean to "give up with this kid?"  If it means accepting that you may not ever be as important to him as his parents, then yes, give up on that.  It's nice that he likes your kids, that a positive!

Even if they have notes, they can skip a line by mistake.  It happens, let it slide

I wouldn't "give up" with him, but I would certainly stop being "nice" with any expectation that this is going to be appreciated or reciprocated.   Treat him a bit more offhand and stop investing or caring about how he relates to you.  

Based on your description of  your  stepson's presentation in which everyone except you was acknowledged, I'm inclined to believe that the exclusion of you was intentional. I would find this unacceptable, and If it was me, I think I would have to speak up for myself, and call attention to the exclusion. I would clearly state to him that I found it to be unkind and hurtful, and that actions such as these are damaging to my abilitly to feel kind and generous towards him, and to my desire to put forth ongoing effort towards developing a better relationship with him. I'd go on to say that I am hoping that he might begin to be more thoughtful of how his actions and behavior affect others, including me, because my hope is to see him develop into a young man who is able to have good relationships with others. This likely won't change a darn thing, but you'll have stood up for yourself, AND MAYbe have planted the seed of thinking a little more of the feelings and needs of others in this child. The chances of having any positive effect are greater if you can do this in a matter of fact way, and avoid going off on any other tangents. Were I the parent of this child, I'd be coming down on him like a ton of bricks, and letting him know in no uncertain terms of my anger and disappointment, and that regardless of how he might feel, that I expect better treatment of myspouse from this moment on.    

I would be hurt by the speech as well, especially since you took time out of your day to be there to support him (at least it sounds like you were there). It is a plus that he gets along with your kids, as someone above mentioned. Maybe try to stop giving and caring so much. I know its hard because he's a kid and you probably have motherly instincts since you have your own bios. But we don't have to let them hurt us. That's something I am trying to come to terms with as well.

I get it. I've been with my stepdaughters 12 years (23 and 19). One day the younger comes home from work or somewhere. She had gone by a candy shop that has "vintage" candy and such. She brought everyone in the house something except me. My husband, my sister-in-law, my other stepdaughter. I hate myself for getting hurt by things like that.

Yep!  “Bio mum is probably behind a lot of his attitude towards me.”  The below didn't come from me, but I think it is food for thought:  

If your husband was previously married to someone with one of many Borderline Personality Disorders (BPD), You cannot have a relationship with these people or their children. To stay in a relationship with your husband, you cannot have a relationship with the step kids; it is too threatening to the BPD. If the stepkids also are BPD, they will not allow you to have a relationship with your partner, and it will never change.

BPD causes extreme fear of abandonment, and a BPD will require absolute loyalty from children and will try to personally destroy any threat to their relationships with their ex and their kids, especially step parents. They will punish anyone who doesn't give them their way, and will create drama in order for their ex and children to rescue them. The BPD will go on dramatic punishing verbally abusive rants whenever they sense the possibility of abandonment. They fantasize that relationships still exist with ex'es and may become stalkers.

The bio parent complies with the drama out of emotional blackmail and self preservation. The step kids comply out of self preservation because they know there will be hell to pay if they don't prove their undying loyalty to the BPD and disloyalty to the step parent or to the biological parent.

Does that pattern sound familiar?

he could remember his bio parents, his full siblings and stepsibling but left out stepparent. How did hubby not say to his son that it really upset him that he didn’t even mention his stepmum, that he excluded her.

one of my sil is in a blended family, her 2 youngest skids actually refer to their half sister to other people when asked “same father, different mother”, people just look at these kids like wtf?

Kids are kids, can be forgetful and can be mean.  You are not a kid.  Quit fixating on not being mentioned in his speach about family.  Did he go into detail on BM's SO and the SO's family?  If she has an SO.

This is a non issue in the relative scheme of things.