Perhaps the anon who said Bono needs money is right - Form 990 attached for Bono's charity, The One Campaign, for five years to 2016 (2017 not available yet)

2016 ran at a loss of $19,686,328. Sauce : .amazonaws.com/one.org/pdfs/ONE_Campaign-2016_Form_990_public.pdf

Interestingly, Bono is not on the (very well paid) Board. Neither is Matt Damon, founder of water.org, on that organisations board.

They seem to lend their name but by not being "board members" avoid responsibility for anything that may go wrong.

Many of the donations for both come from a handful of people/organisations (names redacted for privacy) but it does appear like the charities send monies back and forth between each other.

Pics related.