Brats go up to vandalise superior hostelry (9)
I believe the answer is:
gastropub
'superior hostelry' is the definition.
(a gastropub serves high-quality food)
'brats go up to vandalise' is the wordplay.
'to vandalise' indicates anagramming the letters (I've seen 'vandalised' mean this).
'brats'+'go'+'up'='bratsgoup'
'bratsgoup' is an anagram of 'GASTROPUB'.
(Other definitions for gastropub that I've seen before include "Place for beer and good food" , "Bar serving high-quality food" , "Local with good food" , "Bogus trap (anag) -- somewhere good to eat and drink?" , "Eaterie" .)