First, the fact that he is in recovery for 12 years is good, especially if they have been continuous. Now, if he is attending AlAnon, in addition to AA like I do, because he has A's in his life (ie parents, siblings, children, and sponsees) great.
When I started attending AlAnon, I was 3 years sober and my husband was 5 years sober, but something was wrong. AlAnon helped me to continue to work on me, and the 'something wrong' eventually revealed itself as him having switched his addiction to gambling.
I have continued with AlAnon all these years, continuing to work on me, as AlAnon has given me a totally different perspective on the 12 steps than AA has, and I do continue to work with AA sponsees.
It certainly will not harm you to try AlAnon, however, I would suggest that you attend different meetings than your boyfriend ....... gives one more freedom to 'open up' in a meeting. In some areas they also have a monthly or bi-weekly meeting of both AA and AlAnon which are quite unique.
I M H O, give it a try, at least 6 different meetings and see if you think you will get any benefit for YOURSELF.
Love and hugs,