Mine showed up on my booking and with the documents I printed out. When I got on the ship and checked the app it did not show anywhere, my reservation to rent an umbrella was there, my reservation for rock circus was there, but no OBC, I went to guest services and they said I definitely had 100. OBC.
Now I can see on my credit card that the 100. was not credited towards my final amount, they never delivered a bill to my cabin so I couldn't check it, I am just suggesting that you make sure you get what is coming to you, I doubt I am the only person this has happened to.