Bergamot is a neat ingredient for herbal tea (6)
I believe the answer is:
tisane
'for herbal tea' is the definition.
(tisane is a kind of herbal tea)
'bergamot is a neat ingredient' is the wordplay.
'ingredient' says the answer is hidden in the clue (I've seen 'ingredient of' mean this).
'TISANE' can be found hidden inside 'bergamot is a neat'.
(Other definitions for tisane that I've seen before include "relaxing drink" , "Herbal tea drink" , "Herb tea" , "Herbal infusion" , "Infusion (eg of herbs or flowers)" .)