yeah, that should be plenty of time. The Premium Terminal is pleasant enough, but frankly it is not that big a deal. Lots of seating areas. Some hot food on a buffet. Some drinks.

But by the time you ride the bus from your plane to the premium terminal (don't get off at the first stop) and then account for riding the bus back to your plane you won't have a ton of time there. They have the transfers down pretty well though even though all of that bus riding is a pain in the butt.

Last year I literally took the bus from my flight from JFK to the PT spent a brief time there and then hopped on a bus back to the exact same aircraft for the onward journey to BKK. If I had known I could have just stayed on the plane...not that that would have been allowed though I suppose.