So far the only Magus that hasn't had the option to go to Nedaria's Landing has been the one in Butcherblock. I've gone there from South Ro, North Ro, and East Commonlands. My first attempt to get there was through Butcherblock, and apparently that Magus isn't good enough to do that port yet. /shrug
My second attempt was to follow what I had heard recently that the way to the zone was through a tunnel in Jaggedpine past the faeries. I almost died, and all that happened was I went back to the port stone in Surefall. Glad to know that it's behind the oracle now in the gnoll caves. Too bad I massacred them when I was told that the gnolls raised JP and Qeynos faction (didn't know about the OTHER gnolls until this week), and once I killed the oracle, I became KoS to them all. I'm sorry little doggies!