I think it depends on year. There was the original RTS (1992/3 iirc) which was America built and the first of its kind. The Team, 1, 2 and 3 followed afterwards, with the team and 1 also USA built, the 2 and 3 made in Taiwan.
When the LTS arrived there was an RTS still available.i assume this was leftover frames some off as bikes, decals were different iirc.
Component spec was obviously different, with the 3 the lowest spec. The team I think was frame only GT Tech Shop.
All usa built were 6061 alloy with a flat cap top tube, Taiwan built were 7001 alloy and had a domed top tube cap. If the frame differences aren't enough, the serials tell the story, USA built have the zaskar style which have month and year in the serial as well as the number of the frame, the others don't tell you much as are just plain serials.
Hope this helps.