Rails Girls Summer of Code is also a non-profit organisation and has many sponsors. I like what they have done with sponsors logos:
There is also text below logos:
Note: the stars on the logos represent the number of RGSoC editions supported by the sponsor
So the idea the more years sponsor supports, the more stars it will get. I think we should do this for RubyAU as well. It’s another way to recognise community supporters and encourages to support more.