The NXT stars that travelled on the WWE bus are not paid extra to appear as Rosebuds on WWE TV. They are paid the same salary that they are paid under their NXT deals. WWE does pay for their travel to the shows.
WWE has been using Rosebuds from NXT if they are within driving distance. In other cases they have been using local talent. Former TNA Knockout Taeler Hendrix was a Rosebud on an episode of Raw.
Speaking of NXT, Solomon Crowe will be repackaged when he starts on the main WWE roster.