I am not sure how GWM and tavern brawler should work together.
GWM mentions:
- When you crit or kill with a melee weapon you can attack as a bonus action.
- When attacking with a 2h weapon you can trade +10damage for -5 hit chance
- It does not mention anything about throwing
tavern brawler
- add str bonus to hit and damage for unarmed, improvised weapon and thrown

Prof. Dr. Dr. Mad S. Tist

World leading expert of artificial stupidity.
Because there are too many people who work on artificial intelligence already