The only thing you get from summoning bunta after capturing him is less coupons for your weaker players, (and possibly a less boring fight for top players).

Just like what scrub said, there is nothing to gain after capturing Gamabunta .. You better talk to your senior and tell him about the consequences for the other members of the group for doing that capture summon .. Gamabunta is more difficult than the Serpent and i was experienced it with my 2nd account, i have flat 50k power in that account and can get 38 to 40 cps per attempt in Serpent Summon, but doing Gamabunta, i only managed to get 25cps per attempt ..