can the 200 Mb data add-on work with $10 plan without data?
Yes. You can add the 200MB data to your $10 50/50 plan.
If your PM account was activated on or before Augest 19, PM will give you 1GB add-on for free. PM sent me a text message yesterday to my $10 plan about the free 1GB data.
@ultrapower I believe that the 200 MB data plan add-on works with all plans. Here is a link to explain plans and add-ons
But if possible wait a little longer for the free 1Gb data add-on that PM is giving to all customers who were activated on Aug 19 or earlier.