​​​​​​The Department of Agriculture, Water and the Environment is the Australian Government department most directly responsible for supporting the Australian wine industry.

From their website's Farming, Food and Drought section, below is content from their page on Wine Policy:

The Department of Agriculture, Water and the Environment supports the Australian wine industry by providing advice to the Australian Government on matters related to wine including international market access, taxation and industry structure.

The department works with Australian winemakers and grape growers, industry representative bodies, other government agencies and international organisations to provide this support and advice.

Wine Australia is the Australian wine industry’s statutory research and development, marketing and regulatory body, and is funded by levies. The Authority provides export data, market intelligence and other general information for the Australian wine industry.

The Australian wine industry is subject to a number of Commonwealth laws, from taxation to export regulation. The legislation specific to the Australian wine industry is the Wine Australia Act 2013 and the Wine Australia Regulations 2018. These provide for, among other things, the Label Integrity Program and the Register of Protected Geographical Indications and Other Terms.

The Act and regulations give effect to the Agreement between Australia and the European Community on Trade in Wine which facilitates wine trade with the European Union—the Australian wine industry’s largest export market by volume.

Data relating the Australian wine industry, including export statistics, can be found through Wine Australia.