There's no claim of anyone seeing a resurrected Joseph Smith that I know of.
Though, Mormon theology would suggest it, it would be generally accepted that he has taken on an immortal form like Jesus did. Not only him, but anyone who has been baptized into the church and has moved on from this life. That's why we have temples. Because earthly ordinances such as baptism are required prior to resurrection, that work must be done for everyone, and by everyone, I mean everyone that has ever lived. The church has baptized on behalf of deceased persons in the hundreds of millions if not billions. Genealogical records done by our church are the most thorough and extensive archive in the entire world by a long shot.