i'm not entirely sure how bounty flags work but i think you need to turn them on for player 1 instead of neutral hostile. if i'm wrong it's not my fault >_> lol
Set the gold bounty fields to zero, leave bounty disabled, and set the "point value" of the hostile units to the gold bounty. Then you can use the following trigger:
Bounty
Events
Unit - A unit owned by Neutral Hostile Dies
Actions
Player - Add (Point-value of (Dying unit)) to Player 1 (Red) Current gold
You could also add some floating text above the unit to duplicate how it shows the bounty from the kill.
"killing unit is owned by (player #)" where # is the player you're giving the gold to. without this condition in the trigger, you just give player α money every time player ß had a unit die