As Wes said, but in different words, if the firearm is subject to sales tax, then the FFL fee is also subject to sales tax.
For a PPT, the firearm is not subject to sales tax, so the FFL fee is not subject to sales tax.
For other FFL transfers, the firearm is typically subject to sales tax, so the FFL fee would also be subject to sales tax. Exceptions are if the firearm is coming from a private party in CA, is an occasional sale and not from a business, as well as a C&R firearm from out of CA from a private seller, is an occasional sale, not from a business, and the buyer has a C&R FFL.
FFL Transfer/Special Order Dealer since 1993.
Net-FFL list maintainer.
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