How cool! Found this growing up a tree in my yard, but what is it?

I’ve just noticed this growing on the trunk of a tree in my yard. I definitely didn’t plant it but moved in less than a year ago so could’ve been planted by previous owners. I’m more or less in Brisbane, and the tree is definitely non-native.

In addition to what it is I would also love to know if it’s possible to propagate it and get more of those white leaves!