That is a correct observation. There is a distinction between our known and familiar 'physical matter' and this 'subtle matter' that is of a higher dimensional and vibrational level as to be undetectable by physical matter. 96% of the matter in the universe is not detectable by physical senses and instruments.And this astral and mental "matter" (matter might be the wrong word since it usually refers to actual physical matter) can only interpenetrate biological bodies?
If I understand the last part of your question correctly the answer would be this matter exists on its own plane and can interpenetrate any denser plane without the denser plane detecting it. Entire astral landscapes can be created on the astral plane of astral matter. Telekinesis which exists but is almost undetectable on the physical plane is quite a force on subtle matter.