Traditional union can open doors for you perhaps (3,6,3)
I believe the answer is:
old school tie
'union can open doors for you perhaps' is the definition.
I can't judge whether this defines the answer.
'traditional' is the wordplay.
I cannot really see how this works, but
'traditional' could be 'oldschool' (I've seen this before) and 'oldschool' is found within the answer.
The remaining letters 'tie' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for old school tie that I've seen before include "Emblem of a person's education" , "Upper-class emblem of loyalty" , "something to wear with advantage?" , "Term for group loyalty of those with posh private eduction" , "Symbol of private education" .)