Would appreciate some advice here. I am replacing the Ikonboard forums on Top Mud Sites - Rankings of Muds, Forums, Mud Database, Articles, Discussions with VB/VBSEO and VBSEO sitemaps. You can see a (work in progress) preview of the new forums at Top Mud Sites Forum

As I am putting so much up front work into SEO for the forums I might as well do the whole site. How do you handle sitemaps when VB is just one part of a larger site? Do you list the forum as a separate site in Google webmaster then use a different sitemap tool for the remainder of the site or is there a way to combine them? I don't want google giving all priority to my forums over the rest of the site. My robots.txt in the site root directory points to the VB sitemap, but can a robots.txt have multiple sitemap: lines to allow for a sitemap with the main page too?

This is one of the last remaining things in the way of launching the new forums, so would really appreciate any advice from others who have their forums as part of a larger site.

Thanks!