I think the reverse order of those words would be the better domain, I.e. onlinejobs.com.au
Job related domains do sell well under normal circumstances. However, I don't think it's a great domain that will have buyers lined up.
I know some people don't like domains with 'online' in them, and I've heard them called 'dated' etc, but I still like the high quality ones. People still use the term 'online' a lot. I've spent a bit of coin over the years on ones like onlinetraining.com.au, onlinebusiness.com.au, etc.
Behaviour is changing rapidly, with a huge increase in online activities given the COVID-19 pandemic, so I'm also hearing the term more often at the moment.
To summarise, not a great domain, but you may get lucky with a sale on the lower end. Good luck!