I\'m thinking of starting a project to make a game, maybe just a simple one, but still a game in 3D for the IPhone.
Though i still have a long way to go, learning object
I cannot speak of whether or not it is a good idea to learn OpenGL before hitting OpenGL ES. However if you are interested in learning OpenGL there are several things you need to ask yourself, like what platform do you want to use, and in what language do you want to develop.
I do think that you would benefit from it, but how much is hard to say.
First have a look at All Public API Implementations, Tutorials and Sample Code
For tutorials here are some that i find useful
C++
Introduction to C++ OpenGL Programming
Java
JOGL: A Beginner's Guide and Tutorial
Multiple platforms/languages
OpenGL Lessons