Phil and Claire were married and Claire had already gotten pregnant with Haley. Phil got married in a tuxedo which he let Dylan wear in "Baby on Board" to go to prom with Haley; as for Claire, it is unknown what she wore, but in "Other People's Children, she mentions that she had never worn a wedding dress, which may leave a hint that she had just worn a dress that went all the way near the end of her legs (If it's possible). Jay never got to walk Claire down the aisle.
Because of Claire's pregnancy with Haley, Phil and Claire never got to have a honeymoon and were actually planning to go to Hawaii for it.
In the episode "Hawaii", Phil and Claire had a re-wedding to renew their vows and Jay got to walk her down the aisle.