Will I?

as far as i know, nope.

For any game or bundle, add it to your cart and proceed to checkout. It will tell you if you already own one or more games in your shopping cart, and will tell you whether or not you will receive additional copies or not.

Where does it say you'll receive additional copies?

(If I put it has a gift into my inventory do the two separate into two gifts? like Bioshock and the season pass)

Valve Games are the only ones that offer gifts and only with certain games

BioShock Infinite will not give you an extra gift sorry save your money

You may want to check with amazon and see if they offer it at the same price and if it comes as two keys

Awh okay, ill go check.
Thanks.