Hiya Rosy,
If I understand you correctly, you’re looking to use a WP site to generate a link that will promote your Book o’ Ra site.
Well, that’s just fine, SEO-wise, from what lil’ I know. I mean, that’s the heart of SEO right there, linking!
Just don’t, as Ipstenu seemed to have said, link back to your Ra site from any site that’s linking to it.
And BTW, esmi, I didn’t know these forums are only for self-hosted sites! Thanks….