In my (one time, so far) experience, that would not be enough time. They are right across the hallway from each other, but we had to wait a bit after check in (I guess for a changing room), and then a few minutes more for the stylist. The actual makeover didn't take that long, though. You don't want to be looking at your watch and stressed the whole time about making your CRT reservation.
Another consideration is whether you want to take advantage of the (free) photoshoot at Castle Couture afterwards. If you have Memory Maker, all of the photos are included on it, but if you don't, you can purchase them individually. It didn't take long for the photoshoot, but we also had to wait there for our turn, too.
I suggest an hour and a half. You may have some extra time afterwards, but you can walk through the castle and look at the beautiful mosaics.