When Amy first signed it in "The Flaming Spittoon Acquisition" (S5E10), she found signing it very romantic. By "The Spoiler Alert Segmentation" (S06E15) she called it a ridiculous contract right after Sheldon said that she couldn't move in with him. She also liked the fact that the agreement is binding. With the dissolution of Sheldon and Amy's relationship in The Commitment Determination, it can be assumed that the Relationship Agreement is now void. It's later implied that the Agreement was reinstated after they got back together, as Amy brings it up in The Viewing Party Combustion.