Your home state of New Jersey is part of a Driver License Compact (DLC) which allows state DMVs to exchange information about citations received out of state back to the state in which you are licensed. A few states including Massachusetts, are not members of this compact.

Even though MA is not part of the DLC, according to their Registry of Motor Vehicles the state has arraigned to share driving record and violations with other states. This seems to indicate that MA will indeed send your speed ticket information to the NJ Motor Vehicle Commission.

The NJ MVC ensures that out of state violations become part of your NJ driving record once this information is received in to them. The MVC has also determined to assess 2 points for each out of state moving violation that a driver receives.

So it would appear that if you plead guilty and pay the fine in MA, your conviction information will be shared with NJ and points will be assessed. For more information regarding this situation you can contact the NJ MVC.