Joking that banks are where the money is?

Yes.

There is nothing wrong with joking among friends that banks are places where money is made, because banks are places where money is saved. Metaphorically speaking, banks are places where money is made without exaggerating the facts. It can be used as a joke after dinner.

Joking means teasing others in a humorous and relaxed way, which is acceptable to both parties. It also expresses pride and affirmative tone, but also treats it with a non-serious attitude and treats it as child's play.