Why go
A pub can introduce regional beer, but familiar glass names do not mean the same volume everywhere. Asking about the size avoids a surprise at the bar. Local wine and independent breweries offer other choices; check the particular venue or bottle shop for what is available instead of assuming a nationwide pattern.
The full story
Beer lists can offer a quick taste of regional identity. Long-established names include Coopers in South Australia, Tooheys in New South Wales, XXXX in Queensland and Boag's and Cascade in Tasmania. You may also find local independent breweries. Ask what is on tap rather than assuming a nationally advertised beer represents the local choice. The language of a beer order changes between places. A schooner, pot, middy or pint may mean different sizes depending on the state and the venue. If the amount matters, ask the bar staff to show or describe the glass. A stubby is a small bottle and a tinny is a can, terms you may hear well beyond the pub. Australian wine ranges from large producers to smaller wineries. A bottle shop is the usual place to look for wine or beer to take away. Retail availability and venue rules vary locally, so check the shop or venue rather than relying on a countrywide trading-hours rule.