Companion is initially opposed to wine (7)
I believe the answer is:
chianti
'to wine' is the definition.
(Chianti is an example)
'companion is initially opposed' is the wordplay.
'companion' becomes 'ch' (Companion of Honour).
'initially' suggests taking the first letters.
'opposed' becomes 'anti' (similar in meaning).
The initial letter of 'is' is 'i'.
'ch'+'i'+'anti'='CHIANTI'
(Other definitions for chianti that I've seen before include "Chain it to popular Italian wine" , "Tuscan red wine" , "I can hit for popular Italian wine" , "Wine produced in Tuscany" , "I can hit (anag) - alcoholic drink" .)