Le cheval

Mes durs rêves formels sauront te chevaucher,
Mon destin au char d’or sera ton beau cocher
Qui pour rênes tiendra tendus à frénésie,
Mes vers, les parangons de toute poésie.

Het paard

Mijn harde vormelijke dromen zullen je weten te berijden,
Mijn lot is de de gouden karos, en als knappe koetsier 
houd hij als teugels razend strak gespannen,
mijn verzen, toonbeelden van poëzie.

vrij, associatief:
Met vormvereisten zal ik je temmen
je voor mijn gulden karretje spannen
En in een uitzinnige galop
gaan wij dichtend naar de wereldtop.

Horse

My hard, formal dreams will know just how to ride you,
My destiny in a chariot of gold, will be your handsome driver,
Who will take for reins, drawn in tight frenzy,
My verses, paragons of all poetry.

tr. Lauren Shakely

This sounds like a statement on the art and craft of poetry ... See below Apollinaire's his own explicatory note, which however obscures as much as it clarifies.

Some tensions : The 'gold chariot' refers to Apollo, leader of the Muses and bringer of light (Phoebus Apollo, identified with Helios, the Sun). It is also an image of a triumphal procession. Apollo's chariot, however, is drawn by four horses, not by Pegasus.

Pegasus is the Poet's Horse: His hooves touched Mount Helicon (or Parnassus) where Muses dwell, and Hippocrene (litt: Horse's Fountain) sprung. The water from that well is the source of poetic inspiration. The young hero Bellerophon got the idea/hint to use a gold bridle to bridle the untamable Pegasus, while sleeping in the temple of Athena.
In short: both Pegasus and Apollo are closely connected to Art and Poetry (the Muses). Their myths were still quite common pictorial themes in Apollinaire's days, e.g. the symbolist etcher/painter Odilon Redon (link to two pictures of Pegasus below).