First of all, be aware that there are limitations on traveling to Australia under a work visa, so check the exempted categories and occupations carefully. Australia recognizes de-facto relationships - provided you can show evidence that you are a genuine couple in a monogamous relationship that is genuine and continuing and ideally you're living together.
Can I obtain a dependent visa for an unmarried partner?
My family and I currently live and work in Brunei. My employer wants me to take over an executive positive in western Australia and sponsor me. I hold dual citizenship in Germany and the U.S. I am not married to my partner. She is a Vietnamese citizen and we have a son together, who is a German citizen. Both parents are listed in his birth certificate with the fatherhood officially declared. I assume that I can bring our son to Australia without any issues, but I worry about my partner. How can I apply for a visa for her so she can stay in Australia with me and my son?
If you are being sponsored by an employer, your de facto partner and your child can both be included as secondary applicants. She will need to meet health and character criteria, and you will need to provide evidence of your de facto relationship as part of your visa application.
You can include the members of the family unit.
You need to satisfy and meet the proof of de facto partner to be able to include your spouse. These include the nature of the household aspect, commitment, social aspect and financial aspect.