I have been guest posting at a variety of reputable blogs in my niche.  I generally write once or twice a month and have a bio link with a link to my blog.  I'm wondering if multiple links from the same domain (but different pages) helps, or if there are some diminishing returns here. Should I only be writing one post for them?

Of course, there are other non-SEO benefits too, because these are reputable sites.  But I'm wondering how this helps my SEO?

Thanks in advance!