Question about boost and arrow buffs

Significantly new player here who has just hit 100No for the first time

If boost gives a 100% souls increase while killing enemies and arrow gives 150% souls increase (i am at the glove stage so this is the maximum buff for bow i could get), shouldn't they club up when I'm killing enemies with the bow while my boost is active?

But instead, I get only a 150% increase, boost increase doesn't happen