Pages, Keynote and Numbers download for free

Hi

I bought an iMac on the 7th Dec 2013.I was told pages, keynote and numbers were free. However, it is not installed on the iMac or in Purchases. I bought the iMac with my old Apple ID and have set my iMac up with a new Apple ID as my son uses the old one. Do I need to use my old ID for pages, keynote and numbers to download or can I still get them for free using my new account?

Many Thanks