Valinor and Frodo

[Legolas]

I thought The Ringbears and GImli went to Aman too; yet they were still mortal. Tuor went to Aman, didnt he? I didnt think they were restricted.

Those mortals allowed (Frodo, Bilbo, Sam, and Gimli) were exceptions, granted permission after their great deeds in the War of the Ring. In particular, Frodo, Bilbo, and Sam were allowed in hopes of easing their pain as they tried to cope with life without the Ring. Gimli was allowed on account of his great friendship with Legolas, and the favour he found with Galadriel.

Tuor, for his great deeds in Gondolin and obedience to Ulmo, was granted immortality so he would not have to separate from his wife, Idril (Turgon's daughter).

Also, theres an explanation of Mortals in Valinor on the Barrowdowns regular website FAQ.

Bravo for the reference!