Linking your website with Google+ page made certain difference in Google SERP and as well you will get authority to your website.
Linked website with Google+ page is looks like image below.
Steps Link to your website
1. You should have Google+ as your page(Business Page) not personal profile page
2. Click Profile button from the left tab and click edit profile
3. In the about tab click Link Website button, next to your website URL. If you have not include your website URL you must include it to see Link website Button.
4. If the website is linked with webmaster tool you will get a message to verify the link. So you should click approve.
Webmaster message is looked like below
Linking a Google+ page to a website not only helps build relationships with friends and followers, but also makes a page eligible to show up on the right-hand side of search for relevant queries which may make the page more discoverable. Learn more