If the distance between Earth and the moon were changed, would the effects be immediate?
The moon's orbit might have changed, but obviously it would take some time before this would become visible. The moon's position iself would probably not be that affected by the event as its inertia is too huge. So the tides would probably not be noticeably affected in the first hours.

I have no idea really how long, but it might not take too long before, depending on what point of its new, elliptical orbit the moon is now positioned - is it now approaching earth, or more or less staying at the same distance, or to the contrary getting farther away - the tides will start to be affected.