You don't get any deals as in discounts, but sometimes cast members will add some pixie dust to your trip by doing things like giving you a free dessert or congratulating you as you go by. If you have your heart set on a particular "freebie" like roses delivered to your room, I'd say just go ahead and order it yourself, as there are no guarantees, and TONS of couples are going to be honeymooning at the same time you are. But if you come into it not expecting anything, I've heard lots of stories of people who have had a little extra magic on their trips.
Cheers!
Heather P