As far as I know, Docs To Go can
not parse RTF files. Double check me on that, though. I've heard good things about
MobiSystems Office Suite which definitely can, and looks quite polished. I've got no personal experience with it. The simplest solution is probably to resave your RTF document as a DOC document. If you insist on the RTF format, I think there are a couple of free or cheap RFT readers out there.
-K