The elite discount is on the beverage package and upgrade from classic beverage package to premium. I believe it is 15%. But you usually can’t get the sale price, if they are having a sale, and your discount. I say usually because I have gotten both at times. In order to get the discount you need to call celebrity. The discount is also not available onboard as far as I know but not 100% sure of that. This does not apply to the “all included” pricing. You purchase that pricing as a package and the only way you can get is if the cruise price goes down. You would need to call celebrity or your TA.