I was just wondering because they are so much a part of American culture, yet they are not commonly mentioned when discussing fairy tales, myths, or legends.
I would classify Santa Claus as a “legend” because he is based off a real person; St. Nicholas of Myra.
The Easter Bunny on the other hand is a bit harder. In Germanic lore there is an “Easter Hase” and some trace the holiday back to the fertility goddess Eostre. I also remember reading in Rosemary Guiley’s The Encyclopedia of Witches and Witchcraft about Romanian folklore concerning rabbits and the book having this picture of a female humanoid rabbit totem that was found in England on a fair ground after some gypsies had left. It was kind of creepy looking. Anyway, I would say the Easter Bunny is probably more a product of contemporary folklore than anything else.