As the title states, the casting time of Ancestral Bolster III is not being reduced by the celestial version of Mystical Hex Ward II. I didn't check all of them, but I don't think it affects the casting speed of any version of Ancestral Bolster. Mystical Hex Ward (Celestial) (first version from RoR) also wasn't reducing the casting speed of Ancestral Bolster III.
