I am pretty sure Sawyer wasn't traveling around with this kind of bottle of booze in his suitcase. Obviously he found it while scavenging through the wreckage as he did much of his stash. I don't think the bottle belonged to the airlines, but was with a passenger. I am guessing it was Libby. She gave Desmond the boat so he could compete in the race. I think she was in on it with Pennys father (widmore) to get Des to join the race. They worked together to make sure Desmond would end up on the island so he could push the button. She had the bottle to give to Des, a calling card from Widmore...... He really didn't think Desmond was of little value as he told him so sternly. He just knew that Desmond could not choose his daughter over his destiny to push the button and save future humankind. The bottle was a peace offering, a confirmation that he was most valuable after all. Of course, it is all speculation. But I do not think it is a coincidence that bottle was there on that island, it was there for Desmond.