As far as I can see, 'Skull-Splitter & Blessed Tome’s special aoe attack counts as ranged. Resulting in it not gaining temp health from neither ‘Eternal Vigilance’, nor ‘Slayer of the Wicked’, at least not from the special effect.
I base this on the result board where I have a lot of ranged kills as the Warrior Priest of Sigmar using the blessed tome, and the very low temp health return when using the weapons special aoe. It’s possible the ranged damage comes from Smite though, cant be sure.
In either case, the temp health return from the 2 talents seems so low that I don’t think they work with the AOE somehow.