Environment mapping isn't fully supported by jPCT-AE. OpenGL ES doesn't support it, so the 1.1 path tries to mimic it by using a tweaked texture matrix, but as you may have noticed, the results aren't that good. 2.0 ignores the setting. To really use it, you would have to write a shader in 2.0 that does it. ATM i don't have the time to do that, but if somebody comes up with a solution, i would try to integrate it into the engine.