Does the Restoration perk Necromage increase the damage of Destruction spells?
The perk reads: All spells are more effective against Undead

I'd assume it means:
Illusion spells will work on higher level Undead,
Alteration will Paralyze Undead longer
Restoration spells and will do more damage and affect higher level Undead
Destruction will do more damage

But you know how some of these rules work...
I am currently leveling a Destruction Mage but I don't have the perks to test it yet. I'm very actively avoiding anything unrelated to Destruction, Restoration, Enchanting, Alchemy and Speech (only because I can't help it).