I checked a friend of mine's Tour and she does not have the option either. Until VZW actually comes out with a firmware update for the tour (which won't be for a while I imagine) you don't really need it as it will tell you no updates available. The *228 option should be all you need at this time.
Keep in mind too that if you do an OTA update using this feature you will wipe your phone clean and loose all your info unless you have backed up the phone prior. With BB Desktop Mgr you backup, update, load your backup, and then you're good to go. Some of my friends with Storms who did the recent .148 firmware update didn't know this and just did the OTA and lost all their stuff at which point you'll have to take your old phone and your BB to VZW so they can reinstall all your contacts minus whatever new ones u had with the BB prior to the update. But all your msgs and apps will be history.
A "Quickpull" a day keeps the lag away.
Serving proudly, USAF, Land of the free because of the brave.