To be clear and have an actual answer: this is just a joke. Nothing more. No, bribery is not a common occurrence here. I don't think it has ever happened, and it would be really complicated anyway. I mean, what would a bribe even be? Money? Who would be willing to spend money to get unsuspended? Enough money to make it worthwhile for the mod to take action? And then what, they would use some sort of off-site tool, reveal each other's bank details and exchange the dough? I just can't see this happening.
In any case, to dispel any doubt, accepting a bribe of any sort in order to undo a valid moderation action would be dishonest and cause to, at the very least, be removed as a moderator. Please don't read any more into that string, it is nothing but a little joke and does not imply anything more than that at all.