Sometimes they do..... sometimes they don't

.....it depends upon ur opponent...
when ur opponent doesn't give win bonus.... then u have slight advantage over ur opponent....
If ur opponent gives win bonus as much as u did....then ur win bonus acts as a neutralizer.....
If ur opponent gives win bonus...and u didn't...then ...ur opponent will have that slight advantage
If both of u don't give any win bonus...then win bonus won't work...
So if u were winning even though u didn't give any win bonus....it just means ur opponent isn't giving any win bonus either......
Or atleast this is what I think to make myself believe that win bonus does matter......and it completely makes sense.....any way... mostly u are winning because of ur team's quality,formations,tactics etc......win bonuses makes a noteworthy difference when u are facing an opponent who has equal or more quality