To further understand Montresor's choice in bait, I decided to look up the definition of Sherry. Sherry is simply a wine that is fortified with Brandy after the fermentation takes place. This is different from other types of fortified wine because the fortification takes place after all of the sugar has been used up in the fermentation process. This results in a very dry taste. Some types of sherry will have sugars added to them later to create a sweet taste, but this is not the case with Fino, and definately not the case with Amontillado.
Amontillado is created from Fino in one of three ways; Fino is a Sherry that contains a layer of flor yeast on top. This layer of flor keeps the Fino from oxidizing; since Fino oxidized quickly, it was usually drank quickly upon opening. Amontillado is created by either failing to replenish the supply of flor so that it dies, additional fortification of the wine, or simply not adding the flor to begin with and fortifying the fino until it reaches a 17.5 alcohol concentration.
The finer details of Amontillado, in my opinion, all greatly compliment the character and plot of Montresor. In choosing Amontillado as his bait to lure Fortunto, he has chosen a wine that is classier than Fortunto, a sherry he is not familiar with, and has played to Fortunato's ego, knowing that his prey would not be able to allow another to overstep him. Montresor knows that, despite Fortunato's uncertainty of the sherry, Fortunto cannot allow himself to be stepped over by Luchesi.
There is another subtlety to the choice of Amontillado that, I feel, is appropriate. Being that Fino is a very dry sherry, and that Amontillado is a more alcoholic incarnation, Amontillado can be used as a metaphor for the relationship of Montresor and Fortunado. As Montresor states in the beggining of our story: "The thousand injuries of Fortunato I had borne as I best could; but when he ventured upon insult, I vowed revenge." Montresor has put up with Fortunato's disrespect and insolence, but now Fortunato has insulted Montresor himself; so to speak, their relationship has dried up.
Fortunato is viewed as almost a jester, wearing a conical cap with bells to the carnival, but his humor has dried up as well. In a sense, Montresor has the last laugh; a sort of dry humor. To further build on this idea, I looked up dry humor to try and solidify my idea of what a dry humor is. This is a difficult subject to find information on because it is culturally defined. Dry humor, sometimes refered to as deadpan has been defined as "[humor] marked by an impassive matter-of-fact manner, style, or expression," but this is not the only definition of a dry humor. (http://www.merriam-webster.com/dictionary/deadpan) Dry humor takes a step further and defines the delivery of the joke. Dry humor is told without emotion. Montresor, aside from the yelling back and forth, calmly says to Fortunato "The Amontillado!", "Yes, let us be gone." "Yes, for the love of God!" as he seals him into the crypt. Montresor has delivered the last laugh, and he has reconciled Fortunato for the wrongs that were done to him.