Way to plug advantage in Tea Party location (6)
I believe the answer is:
boston
'tea party location' is the definition.
(Boston Tea Party, US political protest)
'way to plug advantage' is the wordplay.
'way' becomes 'st'.
'to plug' means one lot of letters goes inside another (to plug can mean to block a gap within something).
'advantage' becomes 'boon' (both can mean a benefit or asset).
'st' going inside 'boon' is 'BOSTON'.
'in' acts as a link.
(Other definitions for boston that I've seen before include "Card game; dance" , "American city noted for historic Tea Party" , "Commonwealth capital" , "Sob not in the city" , "American city famed for historic Tea Party" .)