Zoro and Usopp‘s dreams have nothing to do with Luffy’s. Mihawk and Yasopp have already achieved them and neither have been associated with the Pirate King.
As characters, they have decided that it is only through following Luffy on his journey that they will achieve their dream, but that doesn’t change the fact that there is absolutely nothing actually connecting being the World’s Strongest Swordsman or a brave man of the seas to the island of Laugh Tale.
Nami, Robin, Franky and Brook are explicitly linked to going to Laugh Tale, Sanji and Chopper are seeking something mythical and non-existent that almost certainly will link to it.
Jinbei’s dream is a bit unique, it does not on the face of it need a trip to Laugh Tale to achieve- could be done by diplomacy, by war or both- but is almost certainly going to need the truth of Laugh Tale to act as a spark for it.
Zoro and Usopp though, nothing to do with the place. It’s a personal desire of bettering themselves. It can be done without anything to do with Laugh Tale, as Mihawk and Yasopp have shown.
I don’t think Bonney will join. But, and this goes for any character, her dream does not need to somehow link with Luffy being the PK. The character has to decide that they will help make Luffy the PK, they can say I don’t think I can do this without helping Luffy on his way, but that dream itself does not need to link to the island of Laugh Tale, because Zoro and Usopp’s don’t.
And for Bonney’s dream in particular, if it does turn out to be something to do with Nika, through Kuma, then quite obviously Luffy is the Nika figure who will achieve it. Because Nika is dead, and has been for centuries. She can’t meet him. She can meet Luffy though, and Luffy will liberate the world. Luffy’s been liberating people and islands since Chapter 2 where he freed Coby from Alvida. It’s kind of his thing. To say a dream about Nika doesn’t have anything to do with Laugh Tale, but Zoro’s does, is bonkers.