Why did the djinn appear after "Dandilion's last wish"?

Question

Yennefer was trying to capture the djinn and believed Dandilion to currently be its "master" and so made him express his wish upon going through the portal.

“The last wish!” repeated the priest. “She made the bard express the last, the third wish. And Yennefer set a magical trap and, no doubt, captured the genie before he managed to escape into his own dimension! Mr. Neville, we must—”

_{The Last Wish, "The Last Wish" VII}

“Get out of here!” she yelled, grimacing ominously. “It's getting dangerous! The whole thing's getting out of control; do you understand? I can't master him. I don't get it, but the scoundrel isn't weakening at all! I caught him once he'd fulfilled the troubadour's third wish and I should have him in the sphere by now. But he's not getting any weaker! Dammit, it looks as if he's getting stronger! But I’m still going to get the better of him. I’ll break—”

_{The Last Wish, "The Last Wish" VIII}

Both of these quotes imply, to me, that Yennefer set the trap to activate when the djinn appeared after fulfilling Dandilion's last wish. However, we know that the djinn wasn't currently fulfilling Dandilion's wishes but Gertalt's.

“He's the one who held the seal which imprisoned the djinn. The djinn's fulfilling his wishes. That's why the witch can't master it. But the witcher mustn't tell her, even if he's caught on to it by now. He shouldn't tell her.”

_{The Last Wish, "The Last Wish" XI}

So why did the djinn appear if the wishes weren't actually fulfilled/completed?

Answer 1

After posting the question I went back and skimmed the chapter and picked up on something I hadn't before. Yennefer told Dandilion to make his last wish immediately upon leaving the portal. It seems to me then that Yennefer summoned the djinn herself somehow on the assumption that Dandilion would make the wish immediately and set the djinn free and then she trapped it.

“I don't know anything about any arses or hallucinations,” said Dandilion proudly. “Or anything about laurel noses: I repeat, that the last thing I remember was an elegant woman dressed in tastefully coordinated black and white. She threw me into a shiny hole, a magic portal for sure. But first she gave me a clear and precise errand. As soon as I’d arrived, I was immediately to say, I quote: ‘My wish is for you to believe the witcher is not guilty for what occurred. That, and no other, is my wish.’ Word for word. Indeed, I tried to ask what all this was, what it was all about, and why. The black-haired woman didn't let me get a word in edgeways. She scolded me most inelegantly, grasped me by the neck and threw me into the portal. That's all. And now…”

_{The Last Wish, "The Last Wish" VII}

Of course she could have "watched" Dandilion somehow so she would only summon the djinn after the last wish which seems likely considering the quote in the question.

“Get out of here!” she yelled, grimacing ominously. “It's getting dangerous! The whole thing's getting out of control; do you understand? I can't master him. I don't get it, but the scoundrel isn't weakening at all! I caught him once he'd fulfilled the troubadour's third wish and I should have him in the sphere by now. But he's not getting any weaker! Dammit, it looks as if he's getting stronger! But I’m still going to get the better of him. I’ll break—”

_{The Last Wish, "The Last Wish" VIII}