Hi Igor,
I think you may be mixing up rel="publisher" and rel="author" mark up here.
By implementing the Google Plus rel="publisher" link on your sites you are establishing your brand to Google. You should use this link to link to your business' G+ page which should be unique to each business (including the two ecommerce sites). (For reference: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=1708844)
Additionally, you can set up a rel="author" link between the sites which you contribute to and own to establish your personal G+ account as an author. (For reference: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=2539557)
Thanks,
K