Item Attribute +1

On my elementalist I have a set of primeval armor for an earth build. The head piece is a bandana which is supposed to give 'item attribute +1'.

I currently have 14 in Earth Magic. (12 attribute points + major rune of earth)
I am wielding an Insightful Earth Staff of Enchanting.
Correct me if I'm wrong, but the bandana should boost my earth magic to 15.

The rune needs to be applied to the bandanna in order to get the +1.

If i bought a normal earth head peice and added a major rune to it, i could have +3 earth magic.

If I add a major to the Bandana will it also give me 3.

remembering always to apply the rune to the head...if it was a major +2 it would come to +3, if it was a superior +3, it would come to +4 etc.

Whatever Rune you apply to the Bandana will be given the +1 item's attribute bonus in addition to the bonus from the Rune. If you put an Earth Magic Rune on it, it will give you a +1 (stacking) to Earth Magic, if you put a Fire Magic Rune on it, it will give you a +1 (stacking) to Fire Magic, etc., just like a Hero's Headpiece Armor.

Short answer, yes. You can also add a different rune at some point and the headgear will + the new attribute

This sucks in many of my builds, because I dont necessarily run the rune to the headgear to save on armor pieces...