It's a comeback for Italian wine (4)
I believe the answer is:
asti
'italian wine' is the definition.
(I've seen this before)
'it's a comeback' is the wordplay.
'comeback' is a reversal indicator.
'its'+'a'='itsa'
'itsa' backwards is 'ASTI'.
'for' acts as a link.
(Other definitions for asti that I've seen before include "Bubbly wine" , "- spumante, It. wine" , "Fizzy wine" , "town in Italy" , "It's a (anag) - wine" .)