A week is a little long. I notified Airbnb and they assured me that they will contact you about this. They manually sent my review notification as well so I was able to kill two birds with one stone.
David
Superhost Ambassador ~ Host Club Community Leader ~ Experienced Co-Host
It;s an ongoing problem - you used to get it about a day after, for the past few months it has been 2 to 4 days before getting an email inviting you to review