Whether you are applying to allopathic or osteopathic schools, on your application all your grades will be listed seperate by year and type (ie undergrad, graduate, post bacc etc).
Post bacc grades (taken as undergraduate credits) are averaged into your GPA in both allopathic and osteopathic schools. The only difference is that if you re-take a course, allopathic schools average the two grades together and osteopathic schools take the second of the two grades and the first one is dropped (they do not take the highest grade! If your grade on the second attempt is lower than your first, the second grade will factor into your GPA, despite the fact you did worse!).
For graduate school grades, allopathic schools do not average them into your undergraduate GPA, however osteopathic schools do.
There you have it.