I'm working "backwards" in my assumption.
Pharaoh had a double dream. When Yosef interprets it, he says, in Breishit 41:32
As for Pharaoh having had the same dream twice, it means that the matter has been determined by God, and that God will soon carry it (Sefaria translation)
It seems that Yosef implies that it may have taken two dreams to make his interpretation convincing.
When Yosef has dreams, it seems that it also took two dreams before Ya'akov seems to interpret it as a sign that Yosef may actually rise to leadership and his brothers will come to bow down to him.
However, while Yosef was in jail, the wine steward and the baker have each one dream, and each of them seem to believe Yosef's interpretation after just a single dream.
I realize that I'm making some assumptions here...
Yosef's suggestion to Pharaoh when he says to him the fact that you had two dreams proves that G-d showed you what was about to happen and it is true. In a way, he's saying to Pharaoh, "you should believe my interpretation, because you had a double dream."
Is there a precedent that at least two dreams confirms that the interpretation is believable? Or, were there some special circumstance (perhaps, when the wine steward heard good news that he would leave jail, he was thrilled enough that he didn't need a second dream to believe Yosef's interpretation?)
Regarding Ya'akov's reaction, we see that he reacts and interprets only after the 2nd dream. Perhaps, he didn't think much after the first one?