My wife is a US citizen and I am not a resident, if we file jointly do we qualify for any credits? i.e. earned income credit, child tax credit etc...

You can file as married filing jointly (MFJ) or married filing separately. It is true even if one spouse is non-resident. In most cases, it is better to file as MFJ. Read Your U.S. Tax Return: Filing Status for Married (http://taxipay.blogspot.com/2008/02/filing-status-for-married.html)

If you otherwise qualify, you can get the Child Tax and earned Income Credits if you file jointly with your wife.