Doesn't Emet basically say himself that his tempering is cured?

"Now my charms are all o'erthrown,
And what strength I have's mine own"

To me, that says the charms (or spell, or geas) that were on him are overthrown, ie. gone. And his remaining power is his to do with as he sees fit. He is no longer compelled to do the will of Zodiark.

I could be wrong, but it seems pretty clear to me.