Earlier this month I received a "Bonus Reward Cert" that appeared to be worth zero points.
My purchases from last week finally showed up and one of them has the 500 bonus points. I never got the offer under "My Offers" on RZ.com, so no need to worry about that despite what everyone was saying a few days ago. As long as you see the Facebook poll points (14) then I think you are good.
It also have a line on my account that says "Spring Bonus Reward Certificate" dated today (3/21) with 0 points. Not sure if anything happened though - no new certs are there.
Few days later a $5 cert showed up and ready for print. It was never added into my account, just presented itself as a printable credit. Maybe this spring cert will be one of those random surprises again. Who knows.
Anyhow... like you I also received this "Spring Bonus Reward" and I will wait patiently to see if anything comes of this. Even if I receive nothing, I'll be happy. BB RZ has been very good to me the past year or so.