Anyone who imagines the airlines are going to pay for their ATP license upgrade are deluding themselves.
I can't say I'm familiar with the exact flight test requirements for the issue of an ATPL in Australia, however, you're going to be undergoing a fairly rigorous simulator program as part of any Command upgrade. Before you're let loose to begin line training, under most circumstances, you're going to do one final sim check. How different would this be to an ATPL flight test? That's what I keep saying. Realistically, you're already doing the test!
It will simply be a box ticking exercise for your company.
When I went to the US to do a type rating last year, the flight school asked me if I wanted to include an FAA ATPL into my type rating. There were only like 2-3 additional items required to be included in my final sim check and I could have had it issued. Unfortunately due to time constraints I was unable to get all the theory done as well, so didn't do it. But my point is, there's not much difference in the FAA's requirements vs CASA's requirements.
You do a PPL test, you do a CPL test, why the hell should you not do an ATPL flight test?!
Finally, even if you have an ATPL, without multi-crew jet time, you're still fairly useless on the world aviation stage. So don't think it's going to make much of a difference there.
morno