Hey, welcome!
To answer your question in short, yes, the GTS is absolutely a higher revving car. Due to gear ratios, power band, and tune, the GTS is meant to be revved higher so it is no surprise that the RPMs stay higher than a GT when traveling the same speed.
The GT (1ZZ-FE) is tuned for fuel efficiency, meaning most of the car's power is down low in the RPMs, and as such, stays at a lower RPM (where the power is).
The GTS (2ZZ-GE) is tuned for performance, meaning most of the car's power is high up in the RPMs, and as such, stays at a higher RPM (where the power is).
Going off of that, being tuned for performance, the GTS is in fact meant to be driven at a higher RPM. Revving all the way out every so often shouldn't damage your engine, provided it is well-maintained. Remember, the rev limiter is there for a reason.
I have owned both a GT and a GTS and have observed the same thing, so it is completely normal.
Have fun!