You're still missing something, here. I'm not sure why you're trying to create a relationship to SiteTree. All Pages are related to SiteTree by virtue of inheritance.

It's working right now because you're only asking for the $Title property, which is part of the SiteTree, but if your SeeAlso field is a TourPage, then you should really set up the relationship as such so you can access the unique properties of the TourPage, as well.

You should never have to set up any relationships to SiteTree. That just.. doesn't make sense.

Setting up a relationship to SiteTree actually makes perfect sense - sometimes you need to provide information about a remote page without hardcoding the URLSegment into the template. Also, thanks to the ORM you can also access any extra fields on subclasses of the relationship (TourPage) without having to specify it manually.