If the voltage is up in the charge range of the battery, (When connected to the battery)
I don't think it's going to get any better than that.
In the case of PV, MPPT isn't getting any extra power, beyond the spec of the panel,
it's just matching the load to the source better. Letting the PV work in it's sweet spot.
With wind, the sweet spot is higher off the ground and faster wind..
To get more power, you need more RPMs.
If your load is too much for the PMA, it will start slowing down the blades.
If your load is light, the RPMs will be higher and less power will be harvested.
So, maybe some kind of MPPT would give you a better transfer of power,
(If your load isn't well matched to the PMA already)
but there is only so much power in the wind at a given speed.