iTunes money

You don't, a balance cannot be transferred between accounts, nor used to gift content nor amounts to other accounts. If you've only just redeemed the card onto the account and not spent any of it you could try contacting iTunes Support and see if they can/will move it over : http://www.apple.com/support/itunes/ww (click on your country's flag, the country where you live, and which is therefore the country on the account ; click on Contact Support towards the top right ; click on Get Help under 'Talk To Us’)