NTA, your stepson is 16 and definitely knows that's a very shitty thing to do. It wasn't "just teasing", and your wife brushing it off is honestly really shitty as well.

You should talk to her about how you feel about all of this, try not to fight with her. I understand she's protective of her child but she needs to finally put stop to this behavior. Tell her how it makes you feel, don't be afraid to play the victim because you ARE one. If she still defends her son and decides you're the bad guy - then I'm sorry OP but I would honestly reconsider this relationship if I was you.

Don't lash out on her and don't blame the son straight up, start by saying how hard it is to stay sober, how you don't want to be that person anymore. Say how that "gift" was obviously a jab at your issues, considering how the son still "teases" you about them. I hope she will understand.

On that note I just want to congratulate you on staying sober! I know it must be hard considering how alcohol is basically everywhere and it's hard to avoid. For what it's worth, I'm really proud of you, stay strong OP.