I use the WordPress SEO plugin by Yoast and have set certain pages to no index, no follow but when I use the Ajax search to look for something, the pages are still being shown in the results.
How do I stop these pages from being found by Ajax?
They are for subscribers only and shouldn’t be able to be accessed by searching for them.
In your case I think the optimal solution would be to create 2 different search instances, one for visitors, one for subs.
On the advanced options panel within the search settings, there is a field on the almost bottom of the page where you can add post/page IDs to exclude from the search results. If you don’t have like hundreds of restricted pages, then you can enter the page ids to restrict from the visitors.