is there a perk that increases energy weapon damage? I know about the radiation damage perk but I'm not sure if that effects energy damage as well.
No, but the Tesla Science! magazines add a perk that increases critical damage with energy weapons. Otherwise, energy weapons are governed by the other perks - so a Laser Rifle is under Rifleman, Automatic Laser Rifle under Commando, and Laser Pistol under Gunslinger.
The Laser and Plasma weapons fall into the same category as the ballistic weapons.
Semi-automatic and single fire rifles - Rifleman
Automatic pistols and rifles - Commando
Semi-automatic and single shot pistols - Gunslinger
Heavy weapons, i.e. Gattling Lasers - Heavy Gunner
Energy and physical damage are only affected by other perks like Lone Wanderer, Bloody Mess, Mr Sandman and Ninja when sneaking and with Suppressors, etc.