One of the most important elements of beautiful photography is good makeup. Even in the Digital Age. While I can definitely apply makeup in post-processing with Photoshop, I am going to keep it real here: I'm a photographer, not a makeup artist. I won't be able to do the same things a makeup artist can.
Good makeup ensures that I will have a good base to work with, and if I have to edit, I can make a woman even more beautiful than she was when she was photographed. Money spent on a specialized wedding makeup artist is oftentimes money well spent, in my opinion. I recommend having a good makeup artist for weddings.
That said, too much time spent on makeup means less time spent photographing. I would encourage you to have an established, tangible schedule for how long makeup will take. Try to push your makeup artist to finish earlier so you can have time for when the photographer arrives. That way, you will have the optimum time for bridal photographs before the ceremony.
Makeup Tips for Weddings:
1) No spray tan.
2) If waxing, do it at least 2 days before.
3) No new products within 3 days.
4) Don't change your diet 1-2 weeks out from the wedding. We don't want to discover new allergic reactions.
5) Go Matte. Gloss & glitter cause more harm than good for photography.
6) If you can go slightly more than usual (10%), the make up shows up better in photographs. It might be unflattering, so I understand if you don't want to.
7) If you don't already, make sure you find foundation that is perfect for your skin well ahead of the wedding. One less important variable to worry about.