I just got off the phone with the Riviera Hotel and was told " NO DRINKS OR FOOD CAN BE IN YOUR ROOM UNLESS IT IS BOUGHT FROM THE CASINO OR HOTEL" I have never heard of such an rule, I was told this is to get you to buy from them.
When you check in you sign a form that say's you will follow this rule or pay the price if caught.
If this is the rule next year I think we would be better off at the Tropicana.