Any link, regardless if it's leading to the home page or content page, helps to increase the overall authority of the site.
What you need to pay attention to when creating a link is that the page you are referring to is relevant to the page from which you are referring.
From my experience with building links on forums, if in a forum thread I have to mention the company, I'll link to their main page, but if there is a page with content that is more useful to the forum thread, then I will post a link to that page. I mean, I look at the problem through the lens of context and utility.