It is a global lawsuit.
An Australian judgment for global damages for cartel conduct can be enforced all around the world. Facebook and Google have assets in a large number of countries and a judgement can be enforced in each of them.
Even if the US wouldn't cooperate (a dangerous move as Australia is an important ally) most of Facebook's money is in Ireland (for tax reasons) and it has important assets in Europe, Israel and many other places that will enforce an Australian cartel judgement.
But is this token funding it entirely with the all proceeds going to token holders?