Below is an example of the 'Related Posts' Tab on a City Page
Please note first and foremost, that you can only add blog Posts to top level City pages, and Neighborhood Pages too.
From an Area Page
Scroll down the page until you find a section 'Connected Times' which has 'Posts' in it. From here, just click on the post you'd like to add and it will appear on the right side. This means the post is successfully connected with your area page, as shown below.