PS Stars is currently returning in phased regional rollouts after being down for nearly a month. Select Asian territories have already regained access, and the USA, UK, and Europe are expected to regain access in the coming days.
There have been contradicting posts from the PlayStation support team over whether points totals will have remained intact after the PS Stars rewards program downtime. Some users have reported that their points have been updated as per purchases made during the downtime, but it is advised to wait until availability is rolled out to major territories and then compare and contrast points from before and after to see if much has changed.