Try the World Religious Travel Assosciation.

The World Religious Travel Association (WRTA) is the world’s premier organization dedicated to leading, enriching, and expanding the religious travel industry.  WRTA exists to bring the trade and consumer together for the primary purpose of promoting and providing quality religious travel experiences around the globe. The religious travel industry includes virtually every segment of tourism and comprises the following seven segments:

• Tour Operators, Cruise Lines, Tourist Boards & Travel     Wholesalers

• Travel Suppliers & Vendors

• Travel Agencies & Consortiums

• Religious Suppliers & Vendors

• Churches, Religious & Non-profit Organizations

• Individuals & Clergy

• Media