Google Authorship and Publisher serve two different purpose.

Google Authorship (rel=author)
lets you establish a verified, two-way connection between your Google+ profile and the content you write (whether on your site or elsewhere).

Google+ Publisher (rel=publisher)
Is a schema.org markup tag that allows your website (which is a publisher) to make a verified connection between it (your website) and its official Google+ pages.


Can you use both?
Of course you can!

Think of it this way...


rel=publisher is for your whole site. You just have to link from your homepage to your website's official Google+ page.

rel=author basically establishes you as the (original) author of the content. You link to your Google+ profile from every page that you have content that is written by you.

I hope that was helpful. The credit for this goes to rel=author or rel=publisher: Which Should I Use & When? which I highly recommend everyone to read if you are still confused about the Authorship and Publisher.