Greater Blessings and Pets

[Apatheist]

Would really like to know if you cast Greater Blessing of Kings on the Pets whether it over-writes Greater Blessing of Salvation on the Warlocks &/or Priest.

It doesn't. Pets count as their own entity with their own buff table.

Warrior shouts apply to all party members within range. Greater blessings only apply to the specific class and treat pets as a class for the purposes of receiving the buff. If you GBoK one warlock pet, it applies to all warlock pets even if you have different pets summoned.

I don't have a hunter so I can't test whether the same is true between warlock and hunter pets.