In the PGtA, the Feat "Streetwise" says: "Prerequisite: May not be a member of the
Aristocrat or Patrician class, possess the Gentry feat, or be a Val." (PGtA pg. 190)
However, many Vals (specifically val'Ossen) have Ranger as their Preferred Class, and any ranger character (except val'Dellenov, where it is specifically restricted) can choose to be the Urban Sentinel variant at level 1. The Urban Sentinel variant of the Ranger gets "Streetwise" as a Bonus Feat (which replaces Wild Empathy), so it is, in effect, a Class Ability. (PGtA, pg. 81)
So what happens if you're a Val who takes Urban Sentinel? Do you lose out on a Class Ability, or do you override the Feat restrictions?
Looking through the LARC and the Updates/Errata, I haven't found any rulings, except where it specifically states that val'Dellenov females are not allowed to take the Urban Sentinel variant. Thus, it seems logical to assume that if the other Val families that have Ranger listed as their preferred class aren't specifically restricted from taking Urban Sentinel Ranger, it's an allowed class for Val.
So, that having been said, I have a val'Holryn (val'Ossen bloodline) Patrician that I want to multi-class into Urban Sentinel. The concept being a noble bastard who serves in the Royal Navy of Milandir (more as a support officer than as a marine officer or command officer) - as such, he knows his way around port towns and some of the seamier side of life that comes with hanging about with sailors, but he also knows and fulfills his responsibilities and duties as an officer and noble of the land (despite his bastard status). To me, the Urban Sentinel variant seems more appropriate than a regular nature ranger.
I could go rogue rather than ranger, but that brings up XP issues, as Rogue isn't a preferred class, so I'd have to keep it even with the Patrician levels, whereas with ranger I can take 4-5 levels to cover his "active service" time, and swing back to Patrician levels as he "moves up the ladder."