It shouldn’t prevent google from crawling your website and should not affect your ranking. using these commands you mentioned:
Disallow: /blog/wp-admin/
Disallow: /blog/wp-content/
Disallow: /blog/wp-includes/
you are simply disabling a login-based webpages that google cann’t crawl in the first place, so if anything you are doing them a favor.
____________
Mike
SEO Software
