It really depends on how busy the videographer is. If he or she prefers to only shoot a few wedings a year, you could expect your video within a month or two or less. Generally speaking, most videographers will be able to deliver the video faster than the photographer will be able to deliver their photos because sometimes it takes longer for the photo labs to develop all the photos and to build the album and deliver the book. If your videographer tells you it's going to take more than 3 months to get your video to you, I would say that's a pretty long time unless they have a good reason for that. It generally accepted that you should be able to expect your video within 2-3 months.
