Wine coming together for traditional event (5,7)
I believe the answer is:
white wedding
'traditional event' is the definition.
'wine coming together' is the wordplay.
'wine' becomes 'white' (white wine is a kind of wine).
'coming together' becomes 'wedding' (becoming wed).
'white'+'wedding'='WHITE WEDDING'
'for' acts as a link.
(Other definitions for white wedding that I've seen before include "Traditional match" , "Traditional marriage" .)