A bottle for the artist in the snack-bar (6)
I believe the answer is:
carafe
'a bottle' is the definition.
(I know that carafe is a type of bottle)
'artist in the snack-bar' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'in the' means one lot of letters goes inside another.
'snack-bar' becomes 'cafe' (I am not sure about this - if you are sure you should believe this answer much more).
'ra' put within 'cafe' is 'CARAFE'.
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for carafe that I've seen before include "Open-topped glass container" , "Wine, water, jug" , "Serving vessel for water or wine" , "Water-jar" , "Wine server" .)