This book happened to be perfect for my current project, a game-like application built entirely in C++ and OpenGL, to be delivered on Apple's iOS platform. Already in chapter 1, Philip Rideout explains exactly which steps should be taken to build a barebones (even stripped down) OpenGL ES application on an iPhone device. He, luckily, restricts talking about Objective C to the bare minimum (glueing your app to iOS) and uses C++ throughout the book.
For me, the 17 GBP I spent were worth it easily on chapter 1 alone, but there's much more stuff covered in this book. Philip throws a lot of stuff into the mix which isn't neccessarily iPhone-specific, but points you to some really nice techniques in both OGL ES 1.1 and 2. The pace is fast and Philip doesn't always go into all the details, which is what I like (he treats his readers as smart people).
As an added bonus, the author is also one of the very few technical writers who manages to put some real humour into a technical book. Many make an attempt, but fail, but the jokes in "iPhone 3D Programming" made me look up if the author was british (he isn't, he's from Colorado).
To the other reviewer who's complaining about what is missing from the book: none of the things you mention are iPhone-specific. Even a very comprehensive book like Jason Gregory's "Game Engine Architecture" will not provide you with all the answers you're looking for. Face it: this industry requires you to go out and research the enormous amount of different subjects yourself, there is no "one book" that covers them all.