Two-Weapon Defense

This feat grants the character a +1 shield bonus to its Armor Class when fighting with two weapons or +2 to its Armor Class when fighting defensively with two weapons.

Prerequisites: Dexterity 15+, Two-Weapon Fighting

Question: So the bonus is +2 in Defensive Fighting stance. What about Combat Expertise (which is essentially "Improved Defensive Fighting"), or simply holding Shift to block?