You can automatically publish RSS to Google Plus using dlvr.it. You can also post to Twitter and Facebook.
First thing you have to do is sign-in to your account at dlvr.it. Create a new route to Google+ as the destination and Blogger RSS Feed as the source. Now they will auto update you blog post for every 15 minutes to Google Plus page.
Right now dlvr.it is providing this facility to Google Plus for only paid users. They charge $9.99 per month. And they auto publish your blog post to Google Plus page and not to Google Plus profile.