Schema type dataset attribute

[1naveengiri]

https://secure.helpscout.net/conversation/2706306434/60367?folderId=3812058

Query:
I have a query about schema data for marking up the pages nicely for Google SERP.

When I run one of our pages through Google like https://search.google.com/test/rich-results/result?id=9d4e67qNsUWPOf9s_69qKg

And then compare it to something that works well, like Trustpilot at https://search.google.com/test/rich-results/result?id=ErWKTvVz1lA53az8F2580g

I can see that Trustpilot includes the "dataset" element which contains details about the organisation of the listing, and the review count, whereas my Wpgeodirectory site does not. Is this an issue, or something I have set up wrong, and if so is it a reason for reviews and aggregateratings not showing up in Google SERP?