My covers band get wedding gigs, although I don't particularly like playing them the money is good. We got a few from recommendation or someone seeing the band. Howver, the majority of wedding gigs we get are through an agent. Other bands I know that play weddings tend to get these gigs through an agent more often than not. My advice would be to send a demo, CV and photo pack to a number of agents booking gigs in the areas you want to work. The positive side for me is that the agent gets us corporate functions as well that tend to be more fun and even better paid (around £1200 for my band as opposed to around £800 for a wedding).