I believe that each of those statements is designed to confuse Americans. "We do not make a charge for service" is not the same as "service non compris". The other two talk about gratuities, not service. I would not leave an American-style tip in any of those locations. And frankly, I think I'll pass completely on the Sol Y Luna experience. There are too many great places to enjoy on the island where the proprietors aren't trying to scam their customers.