Financial match award, relative to win bonus is lower at higher levels so several manager at higher levels can't afford to max that win bonus as often as they could at lower levels.
Win bonus has nothing to do with the cup.
Last season I won the cup, only with victories and I gave lv1 , min bonus, only in the first semi and the final.
Actually Beckstar who started this thread, found the solution a bit later and made this post
http://forum.topeleven.com/tutorials...xt-season.html

I read and followed his method and I won some trebles with that way.
Actually, it doesn't need so much money or sources but is a different way of playing the game because you must use only 15-16 active players.
I don't know if this can be done in higher levels cause there is a lack of many active teams.