What do you do? You do nothing, you are not in charge of his sobriety and he will get the support he needs from meetings and working at the half way house..
If you feel you should go to alanon I think that would be a great idea.. there you will get a lot of support for yourself and learn how to set boundaries and not to be an enabler..
Your BF is only a year clean.. thats not a whole lot of time.. and even though it seems like he is doing well I would proceed with caution. I'm not trying to be cynical, I can just tell you from experiance that the tables can turn pretty quick.