Casey Niccoli actually believed she was marrying Perry Farrell in the wedding scene, however Farrell knew they would not be legally married.
In the scene where Casey calls Perry at the studio, it cuts to the band playing the song "Three Days". The footage in the the movie is the actual recording that was used on the album.
The wedding scene, where Perry Farrell and Casey Niccoli marry, was used as the music video for the Jane's Addiction song "Classic Girl".