Does the setting of "The Cask of Amontillado" play a role in the characters' learning process? If so, what?
It is clear that the setting is meant to give the reader a sense of another place and time...many Latin phrases are used, Montresor is French with a Scottish family motto, and the wine they seek is Spanish--the Amontillado.
The time is other-worldly, the date not certain. The description of the surroundings give an air of Mardi Gras and celebration which provides Montresor the opportunity to draw a drunken Fortunato away from the safety of the crowds as well as a cover for any screams Fortunato might emit.
Learning process? Well, I am not sure much learning goes on for Fortunato. If anything, he learns much too slowly (probably due to the copious amounts of wine he has consumed at the Mardi Gras celebration) and too late (once he is chained to the wall of the cellar amidst the bones of others).
Montresor, too, seems to be giddy at his successful murder. I'm not sure he learned much from the situation other than if a murder is to be planned, it should be done in a cellar during a huge party.