More tea houses where Sloane Square is located (7)
I believe the answer is:
chelsea
'where sloane square is located' is the definition.
(Sloane Square is in Chelsea in London)
'more tea houses' is the wordplay.
'more' becomes 'else' (synonyms).
'tea' becomes 'cha' (cha is a type of tea).
'houses' indicates putting letters inside.
'else' put into 'cha' is 'CHELSEA'.
(Other definitions for chelsea that I've seen before include "West London area" , "W. London football club" , "London football team" , "place of buns" , "The Blues of Stamford Bridge" .)