1. Most caterers don't need to cook up a special meal for a gluten-free guest. Ask if they can create a modified version of what everyone else is getting - most likely they can. My chef recently modified a plate of salmon and linguini by substituting gluten-free noodles for the linguini. The guest felt very special indeed!
2. Just because it isn't on the menu doesn't mean they won't make it. Let's be honest, businesses are trying to make profits and social catering isn't exactly a money tree these days. If you have something specific in mind that you had hoped to serve your guests, suggest it to your caterer and they'll most likely accommodate to win your business.
3. Cake doesn't always suffice as the only dessert. Sure, they come hand-in-hand with a wedding celebration but can be supplemented by another sweet treat. One idea I like is to serve an exotic fruit kebab or a rich mousse-filled lollipop on each cake plate. This adds an upgraded element to the dessert experience and will surely please all palets.
Rememer, while these are tips for those who are in the throws of selecting a wedding venue and wondering about the menu for their special day, these three event tips also apply to incharge of managing their upcoming event as well!