There are a lot of different opinions on cat curfews and weather or not it applies to your area. Essentially it comes down to your local council and their rules and regulations.

Here are some different links that may help you out.

Department of Environment and Primary Industries
Wyndham.vic.gov.au
Surfcoast.vic.gov.au
Yarraranges.vic.gov.au
Ballarat.vic.gov.au
Maroondah.vic.gov.au

Here are some news articles that you may have missed.

Daily Mercury – National 24-hour cat curfew to protect endangered species
The Sydney Morning Herald – Push for 24-hour cat curfew to protect native animals
Warrandyte Community Association – Cat Curfew – Vote Now!
The Age – Feline furious: Yarra Ranges cat owners fight curfew
The Age – Cat curfew to run 24 hours in Yarra Ranges Shire
Sky News – Push for 24 hour cat curfews-hour cat curfew
Herald Sun – Yarra Ranges Council imposes 24-hour curfew on cats to protect native animals
The Ballarat Courier – Curfew For Cats To Start In April
The Independent – Australia To Impose 24-Hour Curfew On All Cats To Protect Endangered Species