According to Delta's website, while you can earn miles on Avianca and get them credited to your SkyMile account, Avianca flights do not generate MQMs towards elite status.

So I wouldn't call them a partner in the sense that Delta and Continental are partners.

My Spanish isn't the greatest and Avianca's website is inexplicably only in Spanish since they revamped their site (as confirmed with a phone call to Avianca), but according to their website, they aren't affilated with any other programs.

On the plus side it only takes 50,000 miles to hit the top tier with Avianca and you reach the first tier after only 17,999 miles.