Couple tips on doing bunny hop manuals or bunny hopping into a manual. You want to find something you're comfortable bunny hopping onto every time, consistently, there's no stacking, you gotta make sure that you can clear it with enough height in your bunny hop that you can get your front end up into the manual position. When you hop up something, you want to land in your manual position already so you gotta kinda account for what you're hopping up onto, and then a little bit of space to keep that manual up.
As you land, again if you have the brakes you can use the brakes so if you're looping out you can squeeze the break and kinda regain your balance. Myself, I don't use a break on my BMX bike so when I hop I have to know exactly where my balancing point is and immediately react the second I land. As soon as you land, again you're going to use your arms and your knees to kind of figure out your balance point, maintain that balance point and if it's say, a shorter object where you can go off the end of the object, you wanna ideally manual off the end, as soon as you're approaching the end let the manual start to drop down , letting both wheels landing ideally at the same time when you come off the object onto the ground again. If it was onto something where there is no end then you can let the front wheel drop and call it a day. That's how you do a bunny hop manual.