Can I recover my filing fee in a California security deposit case?

Yes, and it's an easy thing to forget to actually ask for. Small claims court generally lets the winning side recover their costs, and your filing fee is the most straightforward cost in the case.

Add it to your claim total rather than treating it as a separate reimbursement you'll sort out later. If you're the prevailing party, it comes back to you as part of the judgment, same as the deposit itself.