Personally, I tag everything I do as #TeamAustralia. So it could be as simple as donating the SBD from one post per month to the @teamaustralia account. That way you get to choose which posts earnings you donate to the group account.

At the end of the day, it's for the benefit of us all. Some people might be more generous while others might not be. We'll find out who's who in the zoo pretty quickly. :P