Bestow first class mark: you’ll see it in Cambridge (6)
I believe the answer is:
granta
'you'll see it in cambridge' is the definition.
(Granta is a historical name for the River Cam)
'bestow first class mark' is the wordplay.
'bestow' becomes 'grant' (both can mean to give).
'first class mark' becomes 'A' (top grade in an exam).
'grant'+'a'='GRANTA'
(Other definitions for granta that I've seen before include "literary publication" , "Literary magazine; earlier name of river Cam" .)