Hm, this would be an interesting match up given it's four verses one, with the turtles with natual armour and second hand ninja training. However Bunnie has had most of her teenhood in being a freedom fighter and has a level in technical know-how due to her robotic limbs.
So I'd say, after careful valuations of the combatants, taking into account the different versions of TMNT as well as Bunnie from both comics and SatAM, by my research I believe the logical choice would be Goku would win.