Is Kor-Tirion (or just Tirion in the Silm) considered not to be in Valinor? I know that's the position in HoME because both the Exiles and Eriol/Aelfwine are allowed to reside/abide there (but NEITHER is welcome in Valinor itself.) That's fine for questions like these, but begs the additional question of just WHERE (Kor-)Tirion is? Middle-earth Way, Way WAY West? And what about Alqualonde? Didn't the Teleri live there, not just use it as a dock?
Kortirion was the name of the great tower that Ingil, son of Inwë built in the center of the island of Tol Eressëa, located off the coast of Aman. This was in memory of Tirion, when that city became off-limits to them. A city grew up around Kortirion and became known by that name.
Tirion earlier named Kôr, was the City of the Eldor built on the hill of Túna, near the great ravine in the Pelóri, the Calacirya.
Valmar (Valimar) was the city of the Valar built in the center of the Plain of Valinor, which was inland from the coast on the continent of Aman.
I think the problem may be that we often use Valinor, the Land of the Valar, instead of Aman when we mean the Land in the West, but of course I'm probably wrong.