Inserting Accomodation details into emails requires the use of some of the more advanced Mustache functionality. This isn’t currently well documented in the interface.
As there can be more than 1 accommodation per registration you must use the loop functionality and the Accommodation tag. This coupled with the accommodation tag information. A good example of this will look like:
{{#Accommodation}}
{{FullName}}
Arrival Date: {{ArrivalDate}}
Departure Date: {{DepartureDate}}
Address: {{AccommodationRoom.Address}}, {{AccommodationRoom.Suburb}}
Ph: {{AccommodationRoom.Phone}}
Email: {{AccommodationRoom.Accommodation.Email}}
{{/Accommodation}}