Local search is the latest feature to be added to Google+, in the form of Google+ Local. Like adding YouTube, Google+ Local means users need to have a Google+ profile to get the most out of the local listings.
Now, if you want to leave a review or post photos, you need a Google+ account. If you do have a Google+ account, you can now see Google+ Local, with recommendations and your friend’s reviews, as a part of the site.
For all intents and purposes, Google is slowly incorporating their various features and products into Google+. So for now, do not ask what Google+ can do to improve the product, but how the product can improve Google+. And hopefully improve those horrible engagement figures.