I am aware of one other recipe book produced using Wikipublisher. The most useful tip turned out to be:
(:div class=multicol:)
2 cooking apples, such as ballarat
yeast
cinnamon
etc
(:divend:)
which produces a 2 column list of ingredients in the pdf.
Currently, there are 4 standard book sizes: A5, CH (classic hardback), HU (half US letter) and TP (trade paperback). However, an author can also upload her own sty file to define any page size and page layout she chooses. This is a text file with a sty extension that includes LaTeX commands to redefine *any* of the commands Wikipublisher uses to lay out the book. With a little LaTeX knowledge (OK, sometimes a lot of LaTeX knowledge) she can redefine any layout feature and produce a book to her own specification. There is an example attached to
http://www.wikipublisher.org/wiki/PressBooks/Fortress (scroll down to the bottom to see the link to the style file -- the page describes all the features of this particular book design).
It would be useful to explore a way for the wikibook server to generate a book in epub. The wikipublisher wiki plug-in can already produce an html version of the book and it shouldn't be too hard to teach the wikibook server to run calibre in command line mode and return an epub. I expect we will have to tweak the html of the book into something calibre can digest, but how hard can that be? As I understand it, you can give calibre a set of rules to tell it how to interpret your html into something sensibly bookish.
A "Made with Wikipublisher" page is a great idea.
Hope this helps.
JR