Bilbo's Last Song

[Ardamir the Blessed]

From a few lines in the last verse of Bilbo's Last Song, it seems that a shining object in the sky, whether Eärendil's Silmaril or not, led the White Ship to the West:

Guided by the Lonely Star

Farewell to Middle-earth at last,
I see the Star above your mast!

I have not found this anywhere else, and I think it is intriguing. Is this yet another connection between Eärendil and the Hobbits? And remember how Eärendil's Silmaril led himself to Valinor, and the light in the sky, whether Eärendil's Silmaril or not, that led the Númenóreans to Andor. But what does 'your mast' refer to? Is it the mast of the White Ship, and 'your' is the Elves?