I'm currently on the Voyager of the Seas and confirm they have the exact same type of bike and use the same SPD cleats.
The trainer did come in (while I was streaming a Peloton class!) and charge me $39 for use of spin bikes while not in class use. The $39 charge was the total for the entire cruise. I wasn't too happy (at first) because the bikes sit idle for 23 hours a day, the room and bikes are unlocked and there is no sign saying you can't use the spin bikes without paying a fee. However after reading this post I am reluctantly OK with the fee.
I took their spin classes a few years ago on the Independence of the Seas and thought they were mediocre at best, the instructor had the same Playlist every time and seemed to be just a guy that had done spin a couple of times before.
Now I get to do all my favorite Peloton classes while on the cruise which makes working out much more palatable.