This will disable bounty given for a specific player. Use it on any player whose units give bounty.
call SetPlayerState(whichPlayer, PLAYER_STATE_GIVES_BOUNTY, 0)
However, if you still want the unit to give bounty but just want to disable the tags, then the only way to do this would end up disabling all tags, including JASS texttag
handles.
If you want to be able to retrieve and manipulate unit bounty, there is a script that can do it, but sadly the JASS tags texttags, so you can't hide them without hiding all text tags, meaning that your bounty manipulations wouldn't be visible to the player.