I rent RVs regularly and have a booking with Apollo RV in Los Angeles, CA. That company does have some shady business practices - not only do they not just place a hold on my cc for the $1,500 CDW deductible like the competition does but debit the whole amount and reimburse about ten business days after vehicle return instead - they charge a $30 "administration fee" for this privilege.

In the C&C, this is spelled as follows:
A Bond of $1,500 will be collected at the time of entering into the Rental Contract. The $1,500 will be debited to the credit card account immediately. An administration fee of $30 applies.
They do not accept any other form of payment for the bond except credit cards:
For security reasons, Apollo will only accept credit card or debit card for rental charges paid on vehicle pick up or drop off. Cash payments will not be accepted at rental branches. The Bond on the vehicle is only payable at pick-up by Credit Card.

Question: Could this "administration fee" be seen as a credit card surcharge as defined in CA code 1748.1 (the Song-Beverly Credit Card Act) and therefore be illegal in California?

No retailer in any sales, service, or lease transaction
with a consumer may impose a surcharge on a cardholder who elects to
use a credit card in lieu of payment by cash, check, or similar
means.

They are the most convenient option for me there, by far. Also the cheapest. So just going elsewhere isn't really an option. Still, getting dinged by that fee irks me.