We generally only link books that are indexed as the only advantage of linking books is that they share the recipe data. However, we do intend in the future to put all books in groups so they share info such as Notes, Reviews, Ratings, Bookshelves and Index requests.
We combine the Bookshelves and Index Requests for the different editions to create our indexing queue. The books you list Tommelise are all in the queue. We do link US, UK and Australian editions. If the different country editions warrant separate indexing (i.e. each country edition is on a lot of Bookshelves) then we will index them separately e.g. as has happened with most of Nigella's books. We have just re-indexed the Australian version of Neil Perry's The Food I Love as we originally indexed the US edition. And we will do more as we come across them - so if you ever feel you have editions that should be indexed separately, as there are significant differences between the editions, please let us know by emailing us on [email protected].
One of our next projects is to improve the functionality of the Forum, introducing search and spell checker.
Vanessa - From Bangkok to Bali would have the Bookshelf numbers plus Index Requests from the two editions combined, but 19 total isn't enough to yet place it in the queue.