Ian, I only just saw your message about the tiling. If you have used sikaflex to stop the leaking then the idea of a waterproofing membrane and bond breaker might not be useful.
A membrane is a product that is usually painted onto a prepped surface in several coats. Each coat being laid down at 90 degrees to the last and allowed to dry. Afterdrying the the membrance becomes waterproff and mildly flexible.
The bond breaker is used in a change of direction such as a wall to floor intersection or in an expansion gap in long continuous areas. The bond breaker might be foam or tape or similar material that can deform and allows for flexing of walls and floors without cracking the waterproofing membrane.
Page 4 of this PDF gives you a section showing what I mean. http://www.parexgroup.com.my/images/specification/waterproofing.pdf
All the best with it.

