I don't think jealous is really the right word! I don't think Aemond is in touch with reality enough to be jealous of Daeron, to be quite honest. I do think he was irritated at the mention of Daeron accompanying the Hightower host, though, and it's based on this quote from the book:
Prince Aemond had no taste for such delays, however. He had no need of his brothers or their dragons, he declared; Aegon was too badly hurt, Daeron too young. Aye, Caraxes was a fearsome beast, savage and cunning and battle-tested…but Vhagar was older, fiercer, and twice as large. Septon Eustace tells us that the Kinslayer was determined that this should be his victory; he had no wish to share the glory with his brothers, nor any other man.
He's arrogant and glory hungry in both iterations, and he doesn't want to have to say his brother's helped him win. He fully believes he and Vhagar can win the throne all by themselves, and the thought of another brother getting in his way after he just disposed of Aegon irritated him.
I do think there's the potential for him to be jealous of Daeron if he hears the way other people talk about him. Stalwart, kind, clever, adept with a sword and a lute, the subject of many a maiden fantasy. Aemond is chronically bitchless and no one wants to look him in his one eye so I imagine there's certainly room for him to be bothered by the way everyone seems to love his little brother... especially considering Daeron avoided all the carnage that comes with growing up in King's Landing (in the show). Who wouldn't be jealous of that?
