Without knowing the charge I can't tell you if it's a deportable offense, so for now you should assume that it is and you should help your son find a lawyer who is well-versed in both criminal defense and immigration law.

You should not expect to get your bond money back until the case is resolved, although there are circumstances when it could happen sooner (e.g., a bond reduction is granted; something that more typically happens when a defendant hasn't posted bond).