No. To book lounges I use LoungeBuddy. You type in a an airport, a date and the size of your party and it will show you which lounges can be reserved. I searched a few Australian airports and they did not show up in the 'purchasable' results. There is an option to show all lounges (on the left, after searching).
When searching for Melbourne Airport, I found the following Qantas Airways The Qantas Club
lounge. On the right, it says the following:
Can I make a reservation?
Qantas Airways The Qantas Club does not currently accept reservations. We are working on it and hope to have it soon.
Can I purchase access?
Qantas Airways The Qantas Club is reserved for passengers with specific credentials such as elite status, premium tickets, or other access methods that are required for entry.
You can obviously use this tool to find which lounges are purchasable provided you know the airport you want to purchase for. In that case, I suggest searching for the specific airport and then reading the T&Cs for the results.