The Valar and Maiar are explicitly not a pantheon, just as the House of Stewards are explicitly not kings. The Gift of Men is terribly obvious in that light: they get to strut and fret their hour upon the stage, then go directly to join Ea Illúvatar. The Valar cannot hold them, they go to join the heavenly chorus. The message is not as direct as in his friend C.S. Lewis’ tales, but it’s there.
If you prefer to term Eru, together with the Ainur, a pantheon that would be more appropriate. The Valar are more like the Olympians as the subset of this pantheon most relevant to Arda.
Also, I don't believe it's said that Men join Eru in death. Just that they will take part in the music after Dagor Dagorath. I think you're sweeping numerous other mythological influences under the rug if you choose to view that as predominantly Abrahamic in origin.
