Why have Merry and Pippin in the Fellowship?

[Olmer]

It was just a wishfull thinking. Nowhere said that he boarded the ship, if it were any ships left.
Even Frodo was permitted to sail on the ship because Arwen gave him a great gift: her ticket to ride (I guess it was a real deal:two hobbits counts as one elf, so Bilbo has got his seat too).
But who would give Sam the right to take a place instead an elf?
Who would remember him there to say that he allowed to go to the Blessed Realm?
Yes, Star, I agree, Sam has never left the Middle Earth.
Even if he said, or hinted to Elanor about his destination, he didn't go farther than the Grey Havens, and, as I suspect, spent his last days among the elves, of whom he used to be so fond.