Juvenile center, unlikely. probation, probably.
This is a minor offense, but it was still an offense. The general idea here, is to make him realize it was wrong, and be determined not to do something like this again. If he does that, then everybody should be happy.
It's a shame that $ 35-40 in fake bus tickets will cost you $ 1000.00 or more in legal fees, but that's what often happens.