In an earlier incarnation back in analog tape days I shot like about 350 multi-camera weddings and other consumer events. For wedding vows I used not only camera top mics but also a lapel mike on groom that fed both a wireless transmitter and a recorder in his pocket. Once I had an illegal trucker CB from a nearby highway badly skew the audio on wireless mike but the tape was fine.

You can probably go to a good recording studio and they can probably isolate the freqs of the beeps and take a lot of it away without taking away from the voice freqs.

Audio software today is really powerful and capable of amazing things - like autotune where lously off-key singers sound great after processing.

Digicom ProTools can do amazing stuff like filtering out certain sound frequencies - studio might cost you a few bucks so it depends on how upset your client is and how much you reputation is worth in dollars and how much you charge to shoot a wedding.

You can also buy software like Cakewalk and try to process the sound yourself. Cakewalk is powerful and you can do a lot of sound manipulation - I've played with it and WOW - best bet for a client and reputation is have pros give you a quote for removing the beeps even if you lose money on this one wedding it will pay in the end with future business.

Professional software like Cakewalk or a professional studio could have the beeps filtered and then have the groom simply repeat/re-record the part of the vows that are skewed so that small piece could be overdubbed on your video with you base track audio removed.

Use your imagination and there are several things you can do to make their special wedding video better.