So far I would say it's not safe to assume anything.
I'm more inclined to agree with
@Rickyd , that you need to take some measurements from points on the frame to axle centers to make sure something else isn't bent. A thrust angle alignment simply adjusts the front toe and steering wheel center to match the direction the rear axle is pushing. It will NOT cause a pull in either direction...
There are a few things that can cause a "pull" on a Wrangler:
Tire pressure imbalance, one low tire can cause a pull.
Radial pull, caused by an inconsistent tire casing that causes more drag.. (similar to having a low tire on the front)
Camber, excessive negative on one side will cause a "pull" to the opposite side. Too much positve will pull to the side that is out of spec. If your cross camber is equal there will not be a pull. If negative on one side and positive on the other it will pull to the positive side. If you do have close to equal negative on one side and positive on the other I would question the alignment tech to see if they made certain both tires are at equal air pressure and that the machine has been calibrated recently. Any difference in tire height to the center of the hub, left to right will throw all measurements off...
Excessive Caster differences can also cause a pull but again something would have to be bent on a TJ to cause that.
You describe that it pulls left when you are on the throttle and goes streight when you let off. That describes something loose and moving around when you go from coasting to on the throttle. You need to double check all your control arm and trackbar joints before going any further.