What if my final paycheck bounced?

This actually puts you in a better position than a paycheck that was simply never issued at all, not a worse one. A bounced final paycheck generally means, as a legal matter, that you still haven't actually been paid, so the daily waiting-time penalty continues accruing exactly as it would if no check had been sent in the first place.

On top of that ongoing penalty, there's a separate, additional statutory penalty specifically for a paycheck issued with insufficient funds, found under Labor Code section 203.1. Hold onto the bank notice documenting the bounced check, since that's your direct evidence for this specific penalty.