Prevailing wage in califonia is a non-starter for me. We did a lot of that type of work in high end homes, and I was very well acquainted with MANY collegues who had been involved in prevailing wage wallcovering/painting jobs, in CA. You will be bidding against many who will lie, cheat, and steal their way to a bid. I never ONCE bothered bidding on that stuff. But, to give you an example of what I knew went on (and yes, guys usually eventually get caught and get their license yanked and jail time,....., but that doesn't happen until they've already taken the life out of any honest bid.
For example.:
pay guys near minimum wage and have them work 12/7 s and then pay them on paper what looks like lower hours at prevailing wage. (BY THE WAY,..LAST I HEARD, WHICH WAS 15 YEARS AGO,..PREVAILING WAGE IN LA WAS AROUND 30 BUCKS AN HOUR...MIGHT BE MORE LIKE 50 NOW.)
Pay off whoever will take a payoff..to look the other way.
It is mostly the union that, because it's in their interest,..is involved in catching cheaters.
In a "coatings" bid (commercial/public jobs only). I could swear it seemed like more often that not that the contractor would be paying off an inspector to say he did the required 2 coats when in reality it was 1 coat. One man that worked for me told me his old boss (this was in the 1990s),..had been paying about $30,000 per year cash to different city officials and sending them to vegas etc.,..to keep the jobs coming in. This particular man ended up in Jail, but I think he was at it for a few years before he got nailed.
Good luck on going commercial. If you can make an honest go of it good for you. For me, I never thought it was worht trying so I stuck with the beverly hills type stuff.