Late reply, but for others who are interested. There are shuttles to all the terminals from this location. I've taken it to CT10 across the bridge. They run a pretty efficient operation - they have a waiting room inside and the driver will come in to announce which terminal he or she is driving to.
Also note that the Royal Caribbean terminal 1 is a 1/2 mile (800 m) walk if you can tolerate it and don't want to wait for a shuttle. If you drop your heavy luggage off before returning the car, it's doable if you are able to walk. The distance is about 3x the length of the Oasis class ships.