Avian influenza and human pandemic influenza are different diseases.
Avian influenza is a disease of birds which only very, very rarely causes disease in humans. The strain H5N1 is known to have infected over 100 people in the two years between December 2003 and the end of 2005.
For a human influenza pandemic to become a reality, the current form of H5N1 virus would have to undergo a mutation or reassortment giving it the capacity for easy transmission between humans through airborne droplets as is the case for the normal influenza virus.
There is only the most remote possibility of a human pandemic influenza developing in Australia. A more plausible scenario is the introduction into Australia of a human pandemic influenza virus through travel by a person infected with that virus. For that to happen, of course, the pandemic influenza virus has first to evolve.