Bloodlines aired 1/21/2010 after a long winter break of having previous TVD episodes air (the network reran the first 10 episodes to catch new fans up). In episode 1×11 Elena drove away from the Salvatore house upset over seeing a picture of Katherine who looked like her. She wreck her car and Damon saved her and took her on a road trip. Stefan was determined to find her and enlisted Bonnie’s help to do a locator spell. He went to Gram’s house twice in the episode. The first scene shows Stefan meeting Gram but when he returns that night with Bonnie, Stefan and Gram talk and acknowledge they knew each other years ago.
Gram’s house is located in Covington, GA where they have filmed off and on over the years, including TVD finale season (8).