Hi Spadds and welcome to forums. The old hands will groan at oil threads, so if you don't mind I'll slightly highjack yours.
Your question all depends on whether you have warranty and want to keep it; if not there's absolutely no point going to main dealer for oil change.
Next question; if I have different dealers change oils does it matter if the make of oil differs or is it just important that the viscosity and fully synthetic status is the same (JDM Sti). ?