Excise would actually reduce the price of higher level bottles of wine. The standout example is Grange: instituting excise would reduce the retail equivalent price of the tax take on a bottle of Grange by about $200*.
The part of the industry that would be hit hardest would be cask wine, which would kill the inland irrigated vineyard areas ( Riverland, Riverina, Mildura). Look at the noise they made when Howard tried to fix the overallocation of water and think how any Government would survive that combined with cheap wine becoming more expensive while Grange got cheaper*.
Excise on wine was proposed by Treasury at lest as far back as the GST intro, and again by the Henry review in about 08. It gets quietly dropped every time Treasury proposes it.
BTW last I looked Australian wine taxes were the highest of any producing country.
* Except it wouldn't because Grange is a pure Veblen good.