Alliance Bill

I would like to know about the Alliance bill for a corporation.
1- is it automatically released to the corporation ?
2- I have read on the EVE Uniwiki that is about 2 millions isks per corp/month and one of my corp told me that they got a bill of 6 millions !?! - Is there something I miss here ?

The only alliance member who gets the bill is the executor corporation in charge who pays for all members of the alliance out of their wallet. If an alliance wants to split the bill, the other member corporations would have to manually send their portions to that executor corporation to reimburse them for that expense.