Restaurant coupon/discount service in Australia
In a word, no. The main coupon sites very occasionally have a coupon for a new restaurant but it's usually to drum up business for somewhere middle of the road. The other big thing in Australia is a book of coupons you buy and use through the year. Again, pitched at more local restaurants.
That said, many restaurants run their own offers, usually based around special nights or BYO.
Stay away from them, they are the last hope of failing restaurants and will rip you off. If $20 for a bottle of wine, two mains and a desert sounds like a good deal in Melbourne CBD it's because it is. Pay the extra money and go to a respectable restaurant, trust me. Burned twice by living social, never again. One of the restaurants I got a coupon for went under before I could even exercise the coupon and Living Social will take no responsibility for that.