We have a debate going on in our group about a Druid's ability to share spells with him animal companion.

The short of it is, does the animal companion have to meet prerequisites of the spell, or is it only the Druid that does? Understanding, of course, that the description says spells that don't normally affect creatures of the Animal type still work on the animal companion. (Though I think that applies to spells cast directly on the companion.)

The exact situation is the Druid in our party casting Luminous Armor on himself (from BoED) and having it affect the companion. The requirement of the spell is that it must be cast on a creature of Good alignment. The companion is neutral.

Side A argues that the Druid is the target of the spell, not the animal companion. The companion simply gets to share the effect of the spell, so as long as the Druid meets the requirement, the companion benefits.

Side B argues that the animal companion has to meet the prerequisites of the spell to get the affect. Except for the exception that allows spells not normally affecting Animal types to work on the animal companion.

Which side is correct?