Religious establishment never follows House (8)
I believe the answer is:
seminary
'religious establishment' is the definition.
'never follows house' is the wordplay.
'never' becomes 'nary' (I've seen this in other clues).
'follows' says to put letters next to each other.
'house' becomes 'semi' (I've seen this before).
'nary' after 'semi' is 'SEMINARY'.
(Other definitions for seminary that I've seen before include "Religious academy" , "School of theology" , "Theological school" , "Theological college" , "Religious training college" .)