Yes you need a license. Once you get a license, in some areas that can facilitate a CCW.
I suggest you go here
http://www.leginfo.ca.gov/calaw.html
and search in both the Insurance and Penal Codes under Bail
Assuming you meet all the requirements, the turn around time lately for the Insurance Board for licensing anybody has been 3+ months from requesting the exam, taking the exam and getting the license.
Then you will need to find a bail bondsman willing to take you on and the liability involved.
So don't let me discourage you, it's easy. Would this be something to do under the table? I dunno, get involved with State and Federal Tax folks, Insurance Commissions, maybe the criminal justice system when you kick somebodies door in (or worse), then again it might be a hoot.