The book was written for a North American audience. It has a slight leaning toward the western US, simply because at the time it was written, the majority of
permaculture sites were west of the Mississippi, so I visited those and the site reports reflect that. But I did travel in New England and the Midwest to several sites. I tried to make it relevant to anyone on the continent. The plant lists, principles, and techniques apply to the whole US. And sales are coming fairly evenly from all over the country (again with a slight Western bias), so that suggests people all over are getting use out of it. If you're unsure, see if your library has it or will order it, and check it out. I've also got excerpts on my web site,
http://patternliteracy.com that will give you the flavor.