Naestra & Arahan for beast lore

Since nothing in their rules specifies otherwise, Naestra and Arahan are treated as a single character model, and both would be affected by the spell. Indeed, even their mount would be affected, because the spell description states that the "model gains +3 Strength and +3 Attacks until the start of the caster's next Magic phase," and a character and his mount are also treated as a single character model for all rules purposes (BRB p. 103). There are some stated exceptions, but they do not apply here.