The problem is that the hog was affected by the magical effect when he received the BoAF. In my mind: could you have resisted it, had you MR? If yes, then you were affected. Which is not the same thing as saying that you suffered warping.
To me it's pretty much "one needs to be a Target get warped" (but there are caveats when determining if a particular target under the Target gets warped). This is even one of the key advantages (canon even) of Hermes/Mercere Portals over Form Transportation guidelines.
Of the examples given, I'd say only Curse of Circe warps. A multicast version of Curse of Circe would also warp only once (since the source of the effect is the same spell, which happened to be multicast).
For other examples, as far as I understand Boundary rituals such as the Aegis (which is a bit of a corner case because it comes from a breakthrough) or The Shrouded Glen do not cause warping, because the target is the space within the boundary. Or rather, it would warp the area itself instead of the people and objects living inside the area. Mists of Change on the other hand targets people within the boundary, and would warp the people affected.
Similarly, an InIm spell to look inside a room from afar might warp the room, but it won't warp people inside the room.
As for immunities, I understand that since the target was not actually affected by the spell (only targeted) he does not suffer from warping.