Yep, you are correct. It actually happened under the Napthine government in 2012 although it was originally a temporary ban.
It started with fraccing and csg and then evolved into all onshore activities. Supported by both parties.
It may have the Labor government that put it into legislation.
I recall at the time that the Lock the Gate movement was very active. They had combined with farmers , which was surprising, to form an activism group.
I do know that various councils have their own bans on the practice independently. Bass Coast shire comes to mind. There have also been a lot of opposition to various onshore mining projects in Victoria as well. Farmers are getting pretty involved these days.
As someone else has pointed out, it might not be that easy to get it going again. Also, there's not that much gas onshore in Victoria. There's quite a bit of fake news around that subject that goes back years.
The offshore Bass Strait fields have been in decline for a long time. To the point that they are starting a program to remove some of the existing platforms that have been out there for nearly 50 years.
The halycon days of gas production in Victoria are over.
https://hsfnotes.com/mining/2012/08/28/victoria-declares-ban-on-fraccing/https://www.carternewell.com/page/Publications/Archive/Victoria_widens_moratorium_to_include_all_onshore_gas_development/