The reserve pinot noir is the winery's flagship, produced only when there is fruit of exceptional quality.
The wine won a blue-gold medal in November - its 12th in the competition.
The blue-gold, or double gold, medal was awarded after the wine was first judged on its quality before being submitted to judging alongside food.
Only those wines which scored high enough to be awarded a gold medal in each judging qualified for the blue-gold medal.
Winemaker Christopher Keys said he was delighted with the latest accolade for the wine.
All the fruit for the 2008 reserve came from the School House vineyard in Bendigo.
"This is notable for two reasons - firstly, the quality of the judging gives the Sydney competition great credibility, and secondly, because for the first time the Gibbston Valley Reserve Pinot Noir is a single-vineyard wine," he said.
"It has a beautiful perfume, unique to this vineyard.
"Great pinot noir has a link to a place, a real character that defines the wine.
"This School House Vineyard is simply exceptional. Wines from here are layered and complex," Mr Keys said.
Gibbston Valley Reserve Pinot Noir wine has been a consistent winner since it was first produced in 1995.
Earlier vintages won best pinot noir trophies at the New Zealand Royal Easter Show Awards, the Japan International Wine Challenge and the London International Wine Challenge.
