Should work better with the update that just went live.
Nope. In fact it seems even more bugged.
1.) Im not getting the negotiated sum at all (im getting less)
2.) I dont think im getting per head sum at all
3.) Still only 1 party is being counted, and ive removed 4 bandit groups (although only 1 was directly on the road when i caught them).
Heres a save game where you can test collecting reward.