As long as there are links (ie your grid) on your public facing pages (not protected by roles), google will eventually crawl your site and find those urls.
However, you could also implement a google site map that contains the urls for your feature and submit the site map to google.
In mojoPortal you will see we have site maps implemented for each feature that uses friendly urls, ie CMS pages and Blogs and WebStore, so we have a site map for the CMS pages and for the Blog and for products that we submit to google webmaster tools.
We don't currently have a site map for things that just use query string params in the urls like the Forums, but as I said if google is crawling your site they find those urls anyway. I've had no trouble with the forums on this site, we get lots of search traffic that lands in our forums.
The main thing is to make sure you have well structured markup with headings and good content, otherwise you won't get much benefit even when google does crawl your site.
Depending on the nature of your feature you could implement friendly urls for the items in your grid and/or you could produce a site map either with or without friendly urls, and submit the site map to google.
Hope it helps,
Joe