Board Thread:Questions and Answers/@comment-6016076-20140727132427/@comment-24497113-20140727164622

The Monkey Bank does indeed generate a greater amount of money in Monkey City. The desciption reads that it generates $675 per round instead of $450, and keeps the 10% interest. In addition, the bank can hold a maximum of $7500.

Assuming that the Path 1 upgrades also gained a similar buff to the regular bananas, a 2/3 Monkey Bank would be making $945 plus interest.

EDIT: I have confirmed the above.