Sorcerer Eldritch Knight enhancement:

Force's Point: When you cast an offensive spell, you gain a stcak of Force's Point: Martial (+1 to Hit and Damage). This stacks up to 5 times. When you hit with a melee weapon, you gain a stack of Force's Point: Magical (+2 Universal Spell Power). This stacks up to 10 times. Stacks last 12 seconds each. You may only gain each effect once per second. This works with offensive auras like Eldritch's Aura.
Epic destiny feat:

Arcane Warrior

Usage: Passive
Prerequisite: Level 28

Description

Your weapon and unarmed attacks grant you a stack of Arcane Warrior: Magical (+2 Universal Spell Power).
Your offensive spells grant you a stack of Arcane Warrior: Physical (+1 Melee and Ranged Power).

Each of these stacks to 20 times and each stack lasts for 12 seconds. You may gain a stack of each no more than once per second.

(Spells that are capable of healing via Positive, Negative, or Repair will not provide stacks, even if they can also have an offensive component).

do they stack togheter ?