As we all know, Jason and his company of Argonauts took the Golden Fleece from Colchis. What happened with it afterwards? Is it mentioned in any other story of the Greek mythology?
After reading a whole theoi article, it leaves me very confused and with 2 theories.
The less likely one.
First the bull was sacrificed to the god Ares, and the fleece was put on the holy grove of Ares.
An oracle told Aeetes, son of Sol [Helios], that he would keep his kingdom as long as the fleece which Phrixus had dedicated should remain in the shrine of Mars [Ares]."
Once it came back, it was guarded.
For instance, the report was spread abroad that there were fire-breathing Tauroi (Bulls) round about the precinct and that a sleepless Drakon (Dragon) guarded the fleece . . .
The more likely one.
It was put as a blanket, or bed sheet after Jason and Medea come back, when they were married.
"[In the cave of Makris on the island of the Phaiakians, Jason and Medea consumated their marriage :] It was here that they prepared a great bed, spreading the shining golden fleece on top of it, to grace the wedding and make it famous in story. Nymphai gathered flowers for them, and as they brought the many-coloured bunches into the cave in their white arms the fiery splendour of the fleece played on them all, so bright was the glitter of its golden wool. It kindled in their eyes a sweet desire. They longed to lay their hands on it, and yet they were afraid to touch it."
Robert Graves in his scholarly "The Greek Myths" Ch 156 says: "Jason first visited Boeotian Orchomenus, where he hung up the golden fleece in the temple of Laphystian Zeus." I'm not sure what his original source was for this, it's not immediately clear from the text, though there are references which could be followed. This was after Jason left Iolcos and before he arrived in Corinth