Sounds like you're a real good player, so you'll have no problems. I'm 40, and in recent years have played in three bands with wide age ranges, one including a father-son pair. My most recent band was led by two 25 year olds, the drummer was 32, and the keyboardist 39. Nobody cared. Since rock has been around for about 50 years, its appeal extends across generations, so age is less and less relevant despite rock's initial "youth music" status. And think about classical orchestras and jazz bands, which frequently have players from their 20's through their 60's and beyond.
Just one bit of advice from the hill: don't think this modern stuff like Good Charlotte and Fall Out Boy or whatever the kids listen to these days (wow, I sound old) is actually punk. Having been around, these guys will know it needs to rock hard, old school style -- so get ready to bring it!
(You probably know this already.)
