Most of the old salt in Polish resort is bound to make you feel better (8)
I believe the answer is:
Here is my best explanation:
'bound to make you feel better' is the definition.
I can't tell whether this definition defines the answer.
'most of the old salt in polish resort' is the subsidiary indication.
'most of' means to remove the last letter.
'the old salt' becomes 'tar' (I've seen this before).
'in' indicates putting letters inside.
'resort' is an anagram indicator.
'tar' with its final letter taken off is 'ta'.
'polish' is an anagram of 'hospil'.
'ta' going into 'hospil' is 'hospital'.
'is' is the link.
(Other definitions for hospital that I've seen before include "Place of healing", "Healing institution", "Sanatorium", "Spoil hat (anag)", "asylum?", "medical centre", "medical facility!", "Medical centre", "Institute for care and treatment of patients" and "Has pilot gone there for help?".)