From what I was told, the F&B credit (the ones that are processed electronically) expires at 4pm everyday. It is possible to use it immediately upon check-in. I've used it a couple of times for dinner and got charged for breakfast the following day as the credits haven't posted yet. And yes, the Bistro does have some really good items on the menu - like chicken wings, banana bread toast, butter chicken, etc, just to name a few. I stay quite a bit at the CY where I live, so I'm not sure how it is in other places.