Melbourne's hot new rooftop bar

• Restaurant review: Pascale Bar & Grill, QT Melbourne

Hotel bars aren't usually at the top of one's list when it comes to a night out. They're often catering to a captive audience of unadventurous guests who don't mind paying too much for postmix drinks and room-service wedges over tinkling piano music.

But the weeks-old QT Melbourne is not your average hotel. The local branch of the swinging national chain has spared no expense on its fabulous rooftop bar perched on the 11th floor of the new custom-built concrete tower on the site of the old Greater Union Cinema (RIP).

Punters are greeted in the glossy lobby by glam gals in barely-there cocktail frocks (known as Guest Experience Agents) and ushered skyward via the nightclub-dark elevators into the long, lavish bar canopied with spilling green ferns. It's like a city version of Fitzroy's Naked in the Sky: a sleek, vertiginous watering hole designed to satisfy almost 200 urban scenesters at a time.

On night one it was already packed, ambient house tunes floating across the sweeping terrace, skyscraping towers twinkling romantically in the dusk. Dare I say there's a slightly Sydney vibe here, with beach-chic furniture, miles of oiled decking and a shoulder-high concrete succulent bed sealing in the crowd so no ciggie butts – or worse – can stray over the edge. 

Finding a seat is a contact sport: we pounce on group of leggy drinkers as they inch away from a glowing white plastic table. Then we reach for the menu, a thick document fresh from the printers, with a page of fancy $22 cocktails followed by a tight selection of international wines (no bottle under $50, sorry), plenty of bubbles and on-trend spirits.

Some pop-tastic snacks lend Asiatic cool to standard US classics: a Taiwanese hotdog on a sticky rice bun, or Hokkaido Milk Damper Buns, which despite the alluring name are two small wagyu beef sliders with Japanese mustard and nothing more. It's deceptively cheap given the dainty portions – put your card behind the bar and you could really do some damage.

Cocktails are worth splashing out on; the QT Rooftop G&T is a long-glassed fiesta of West Winds gin and house-made elderflower syrup with cucumber soda and a frond of rosemary submerged in a heap of crushed ice. The Gilligan is flamboyant creation for two ($38) in an oversized brass pineapple vase, holding a deadly mix of absinthe, vodka, spiced rum, and a cloying kick of falernum​ finished with "Frosty Fruit reduction". Yes and yes. 

It's so new and ambitious that there were some early slip-ups from some confused staff (sorry, Guest Experience Agents) who frantically flipped through the bar manual and had trouble keeping up with the crowd. At one point they ran out of almost everything and started pouring cocktails in long-stemmed wine glasses – I doubt that's in the manual.

It's all forgivable because it feels like you could be on holidays up here – in New York, say, or even Hong Kong, part of a burgeoning summer scene that's about to go viral. Finally Melbourne has a hotel bar that's worth checking out, and you don't even have to check in first.