I signed up for this offer earlier last year. After more 30 days passed, no bonus points posted, so I emailed MyPoints, and eventually sent them an attachment of my PeoplePC invoice. Their response?
"We have received your request to close your MyPoints account however we are having difficulty locating the account."
Eventually I got the 5000 points but it wasn't worth the hassle of 5-6 emails back and forth.