Yes, the 50nm rule applies to ATP. See FAR 61.1.b.3.vi.B:
"(vi) For the purpose of meeting the aeronautical experience requirements for an airline transport pilot certificate (except with a rotorcraft category rating), time acquired during a flight—
(A) Conducted in an appropriate aircraft;
(B) That is at least a straight-line distance of more than 50 nautical miles from the original point of departure; and
(C) That involves the use of dead reckoning, pilotage, electronic navigation aids, radio aids, or other navigation systems."[/quote]
Be sure and note that no landing is required at an airport more than 50NM, but the flight must extend at least 50NM from the departure point.