You have two separate WP installs and you have installed Poka in one of the installs but you want to display reviews to other WP?
Is there a specific reason you have two separate WP installs for this? Because the first I could think of is to combine these two installs to a single WP installation.
If this can’t happen I believe this can be made by creating a different connection to the Poka DB and create a custom shortcode with these data so you can use it to your news block but this is will require to be quite comfortable with PHP.
Both WP have the Poka Theme. We do this for more fexibility and performance, so i don´t have any idea how i can setup the different connection to get only the reviews from first database to the second install.