First of all, it's true that Soma is a sacred drink that crucial in the performance of Vedic Yagnas, at least before Hindus lost the identity of the plant that produced it. (It's thought to be ephedra by most modern scholars.). But this verse isn't dedicated to an inanimate object, but rather to the god of the Soma drink, often called Soma but more commonly known as Chandra the moon god. Chandra is certainly an important Vedic deity, being an incarnation of Brahma and the son of the sage Atri; see my answer here.
Now as to the verse itself, most of the verses of the Sama Veda are taken from the Rig Veda, and this verse is no exception. (But I found one verse that's not in my answer here and my question here.) Sama Veda verse 527 is originally verse 5 of Book 9 Hymn 96 of the Rig Veda. As you can see in the Rig Veda Anukramani compiled in my answer here, this hymn was heard from the gods by Pratardana, son of the famous king Divodasa.
Now as to the content of the verse, Yaska's Nirukta provides two interpretations, one of which is that Soma is being equated with Surya the sun god who generates rays to serve different purposes, and another interpretation relating to the soul. Here is what Yaska says:
Soma is purified. Soma is 'surya' (the sun), from generating (prasavanat).
He is the generator of hymns (or thoughts), i.e. of those solar rays
whose function it is to reveal ; of the Sky, i.e of those solar rays whose
function it is to shine; of the Earth, i.e. of those solar rays whose
function it is to spread ; of Agni, i.e. of those solar rays whose function
it is to move ; of Surya, i.e. of those solar rays whose function it is to
appropriate (svikarana) ; of Indra, i.e. of those solar rays whose function
is sovereignty ; of Vishnu, i.e. of those solar rays whose function is
diffusion : such is the mythological explanation. Now follows the
spiritual interpretation, i.e. that which refers to soul. Soma is also
the soul ; and for this cause he is the generator of the senses : such is
the meaning. Or, he thus declares the course of the soul, that it is
variously modified by all its changing manifestations.
The sage Shaunaka, in the Brihaddevata, supports Yaska's interpretations:
- [T]hree (deities) are mentioned with these three (verses), each containing a couplet ... or rather it is Soma who is (here) praised as (representing) the Sun and the Soul.
The three deities being Soma, Surya, and the soul.
By the way, it should be noted that most references to Vishnu in the Rig Veda are references to Vishnu's incarnation as Vamana the dwarf. That's why he's so often mentioned in the same breath as Indra, since Vamana is Indra's little brother (they're both sons of Kashyap and Aditi).