That's not strictly true. Rockstar Games is US company owned by the US firm Take Two Interactive; Take Two is the publishing arm, Rockstar is the development arm. One of Rockstar's subsidiaries, Rockstar North, is Scottish and responsible for the GTA series but Rockstar have a habit of taking over different game studios and changing the name of it to Rockstar [Location] and people tend to focus on the "Rockstar" part of the name and not the actual studio.
Rockstar San Diego (of Midnight Club, Smuggler's Run and Midtown Madness fame) are the people responsible for the Red Dead series, not Rockstar North.