Learning to stabilise your spine by contracting your transverse abdominus is an evidence-based treatment and providing your back pain is related to an instability problem this should help you. If he is trying to get you to contract your transverse abdominus then you should be thinking about gently drawing your lower belly in. You need to be shown how to do this and he should have got you to do this in isolation before giving you the exercise you desribed. Once you have some proficiency with contractong your transveres abdominus you can go on to the exercise you described. You contract the transverse muscle before lifting your pelvix then perform the lifting while keeping the muscle contracted. If that is what he taught you and that is what you r doing then you are on the right track!

The working of the glute max is fine. In fact You have to do this in order to lift and lower your pelvis. Nothling wrong with that and this is because you have to extend your hips with your hip extensors ( glute max) when you push through your feet and lift your pelvis. In fact in a lot people with back pain learning to use and strengthen this muscle is a good thing.

Don't worry too much about the rolfing thing. Ida Rolf created an alternative therapy called structural integration or rolfing and it has been been more or less discredited. The fact that the exercise is identical is just coincidental.

Your therapist will probably go on to give you more movemnts to do that getprogressively more demanding, each time learning to maintain the contraction during the movement. This is part of a standard therapy

Hope this helps