Apparently this is the dernier cri in the Yoga world:

Yoga on the day of your wedding and even at  your bachelorette party (or hen night, as we say in the UK). If you follow a daily practice, why stop just because you get married? And if you don’t, why not include something as cool as Yoga and make it part of the party?

Core muscles and champagne... (New York Times)

This is just starting to take off in the US, and already business savvy companies such as “Yoga for Weddings” in LA popped up to be among the first ones to surf the wave – their slogan is: “Bringing the Deep Breath to the Big Day”.

If you want to find out more (and maybe think over your wedding plans?), the NYT did a nice piece on this.