If you want to do a day trip (or more) to the Hunter when you're in Sydney, it's a perfect choice. They only take you to boutique wineries (some of which only sell their wines at the cellar door) and the insight and banter from the guide (Steve in our case) was quality. A great day out, helped by the fact that Steve really knew the area and the people who live there.
I think they're based in Sydney - contact them here: www.boutiquewinetours.com.au/