Top wine collection mentioned in book? (4,6)
I believe the answer is:
best seller
'book?' is the definition.
(best seller is a kind of book)
'top wine collection mentioned' is the wordplay.
'top' becomes 'best' (similar in meaning).
'wine collection' becomes 'cellar'.
'mentioned' shows a homophone (sound like).
'cellar' sounds like 'seller'.
'best'+'seller'='BEST-SELLER'
'in' acts as a link.
(Other definitions for best seller that I've seen before include "Book bought in large numbers" , "Popular book" , "Book bought by many" , "Blockbuster" , "What many people are buying" .)