The 997TT would go to 1.2 Bar for 10 seconds (on sport+) and would then go back to 1.0

If you see a small arrow pointing up next to the turbo pressure reading, it means you are on the temporary (10 sec) overboost function.

Enjoy it while the climate is still cold. Turbos lose a lot of power in hot climate (35 degrees and up), out of experience.