"Cheers,” for one (6)
(Other definitions for sitcom that I've seen before include "Humorous situation drama, in short" , "Bread, perhaps" , "Type of comedy show" , "'Humorous drama based on situations, in short (6)'" , "Amusing TV programme" .)
'cheers for one' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bar that I've seen before include "See 9" , "Counter for serving drink" , "Pole" , "Counter; prevent" , "Inn" .)