It’s not a thing though and we don’t all know. Use British or British Empire forces, that’s what they were. Australia was never a dominion it is the Commonwealth of Australia.
Australia along with, Canada, South Africa, New Zealand, Newfoundland and the Irish Free state were all know for the early part of the 20th C as having Dominion Status or simply 'Dominions'.
Basically self governing states within the British Commonwealth of Nations - this term fell out of use after WW2 - but accurately describes them within the time frame we are discussing.
So Australia was absolutely a 'Dominion' in 1941 and the term makes sense in differentiating those forces from British and Empire forces.
But I will say no more on this subject but will continue to use the term.