Well, I didn't have any sort of voucher or coupon for a free drink, unfortunately. I had to pay full price :(. The cool thing is that you can take the drinks to go if you'd like. They'll put it in a big plastic cup for you. They also make the drinks moderately strong so you don't feel jipped or like you're wasting your money.
I visited this place twice during my stay at The Signature. Both times I ordered a vodka soda with Ciroc vodka the first time and Grey Goose the second time. Prepare to pay anywhere from $12-$16 for a drink with tip. Ouch. Also, in eyeing their bar, it didn't seem like they had much of a selection, but I could be wrong.
The place is very cozy and chill...it's a nice little lounge. The staff is also very nice and professional.