Winger from Bristol set about on westbound tube (4,5)
I believe the answer is:
tree pipit
'winger' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'bristol set about on westbound tube' is the wordplay.
'bristol' becomes 'tit' (I am not sure about this - if you are sure you should believe this answer much more).
'set about' is an insertion indicator.
'on' becomes 're' ('on' can be mean 'with reference to').
'westbound' says the letters should be written backwards (letters written from right to left).
'tube' becomes 'pipe' (pipes are tubular).
'pipe' written backwards gives 'epip'.
're'+'epip'='reepip'
'tit' enclosing 'reepip' is 'TREE PIPIT'.
'from' is the link.
Can you help me to learn more?