One of the things I hate most about Spanish 21 is getting into arguments with the dealer, the pit, or whomever because they don't know the rules to their own game. In addition to the bonus pays on splits, another one that comes up often on the redouble game is around how much you're supposed to bet on a redouble when your initial bet is the table max (many places will not permit you to ever place a double-down wager in excess of table max). The rule interpretation itself doesn't make that much difference to my EV, but it sucks when there is ambiguity and I have to ask about the rule, demonstrating that I know too much about the game. While as an AP, I should know more about the game than they do, it's far better if they think they know more about the game than me.
I would also think twice before taking an issue up with Gaming. I did this once because I got screwed by a really bad rule interpretation. Within a couple weeks of Gaming ruling in my favor and getting my money back, the casino worsened their rules. The money I got back was worth about 2 hours of EV. If they didn't ruin their rules, I could have probably gotten dozens of hours of play. To make matters worse, the shift manager responsible for making the bad ruling (who ended up eating crow) has since moved on to several other casinos. Now, there are otherwise tolerant casinos where I have a hard time playing because he's ratted me out. Before going to gaming with anything now, I first consider the cost to me (if it's likely to lead to a backoff) and to other APs (if they nerf the rules).