I've carried my Chanel wallet on chain as well as my YSL Kate bag to weddings. I don't wear them crossbody but I like the option of being able to wear them on my shoulder if needed. I tuck in the chain if I want to hold it in my hand like a clutch. I also have the Bottega Veneta Knot bag, and the Dior Promenade bag (both are discontinued now but the Knot might still be available at BV outlets), and both work well as wedding bags too.