It gives it.
Today I saw it. After the match take a closer look at the player who got MotM.
On the window which pops up right away after the actual match, you will see smth similar :
PlayerX - 4% Speed, 1% Finishing, 1% Shooting ( for example ).
The 4 % Is the MotM reward.
However I didn't get that bonus a week ago for my MotM, despite he was the MotM, no 4%. Yes, I won, and I saw my GK was the MotM ). He didn't get the extra 4%. He is 24 y/o 6*.
Last night my AMR took the prize ( 4 1/2* ) + 4% on the window log after the match.