https://bugs.winehq.org/show_bug.cgi?id=38493
--- Comment #3 from Olivier F. R. Dierick o.dierick@piezo-forte.be --- 64-bit is a requirement for the game. I modified the bug report to reflect this.
I tried anyway out of curiosity.
Wine ends with this expected error message when the launcher is run from a 32-bit wineprefix: err:process:create_process 64-bit application L"C:\Program Files\Rockstar Games\Grand Theft Auto V\PlayGTAV.exe" not supported in 32-bit prefix
I tried to run subprocess.exe itself from the 32-bit wineprefix, since it is a 32-bit executable, but it has to be launched from the game launcher otherwise it exits instantly without doing anything.
Note that I could install the game in the 32-bit wineprefix because the installer is 32-bit and it doesn't check if the system is 64-bit when installing the game.