Live around centre of Toronto, so prosper (2,4)
I believe the answer is:
do well
'prosper' is the definition.
(thesaurus)
'live around centre of toronto' is the wordplay.
'live' becomes 'dwell' ('dwell' can be a synonym of 'live').
'around' means one lot of letters goes inside another.
'centre of' means to look at the middle letters.
The centre of 'toronto' is 'o'.
'dwell' going around 'o' is 'DO WELL'.
'so' acts as a link.
(Other definitions for do well that I've seen before include "Flourish" , "boom" .)