Club employee has energy bar, ultimately (7)
I believe the answer is:
bouncer
'club employee' is the definition.
(night club security guard)
'energy bar ultimately' is the wordplay.
'energy' becomes 'bounce' (bounce can mean energy or liveliness).
'ultimately' suggests the final letters.
The last letter of 'bar' is 'r'.
'bounce'+'r'='BOUNCER'
'has' is the link.
(Other definitions for bouncer that I've seen before include "Club doorman" , "Chucker-out for nightclub" , "Club employee" , "Dud cheque" , "A heavy - climbing cricket delivery" .)