Wonder if pub has a shortage of wine (6)
I believe the answer is:
pharos
'wonder' is the definition.
(Lighthouse of Alexandria, a Wonder of the World)
'pub has a shortage of wine' is the wordplay.
'pub' becomes 'ph' (abbreviation for Public House).
'has' says to put letters next to each other.
'shortage of' means to remove the last letter.
'wine' becomes 'rose' (rose wine is a kind of wine).
'rose' with its last letter taken off is 'ros'.
'ph'+'a'+'ros'='PHAROS'
'if' is the link.
(Other definitions for pharos that I've seen before include "Famous ancient lighthouse" , "One of the Seven Wonders of the World, built on an island off Alexandria" , "Lighthouse off Alexandria, one of the Seven Wonders of the World" , "Beacon" , "Ancient lighthouse at Alexandria" .)