From the Virgin Aus website
Non-residents
We are happy to consider non-Australian passport holders for most of our roles however we would typically look for either 12 months minimum permanent residency or a minimum 12 months remaining on your work visa.
We consider applications for sponsorship on a case by case basis however sponsorships would typically eventuate for positions where we are searching for a unique skill set and are finding it difficult to source from the Australian labour market.