La Tulipe Desserts, a European patisserie, is not a dedicated gluten-free bakery, but they do sell some gluten-free products, including award-winning macaroons. Here is some information from their website.
"We can create any custom size, flavors, and style for your special day. Anything is possible. Imagine it and it is yours..."
"Our flavorful ingredients are almost all organic and come directly from original sources around the world — vanilla beans from Haiti, pure lemon and orange essences from Italy, Marcona almonds from Spain, chocolate from France, Lubecker marzipan from Germany.
And that’s just what we import. We buy fresh, seasonal organic produce and honey from local farmers, and we choose it ourselves. Those fruits in your dessert taste fresh – picked because they are fresh – picked.
From start to finish, every creation at La Tulipe Desserts is an individual work of art. No mass production, no prepackaging, no artificial anything. Just premium, hand-selected ingredients prepared by artisans. We invite you to taste the difference."
A photo of Chelsea's cake hasn't been released yet, but some photos from the wedding can be viewed here and in this AP video, which mentions the vegan gluten-free wedding cake. She was a beautiful bride in her Vera Wang dress!