Pleeeeeease do not start any bonding process any time soon! There will be blood as Hermin said above!
Some bunnies can NOT be bonded- period. It is also a long and delicate process.
Another question I have is that you mentioned Bambi is 9 months old and you have had her for 8. Someone gave you a 4 week old bunny???? If so, they are a complete moron.
Also remember that baby or juvenile bunnies are not grown and can change their tune quickly. I have read a lot about bunnies (even siblings) who get along perfectly and boom! they start fighting at 8 months old! That’s because they are not fully mature yet.
I also believe Bambi is protecting her territory and her hooman. My buns have been bonded for years but if I introduce another bun, my two can turn on each other out of confusion or because the new buns smell is on the other one.
At this point in your situation, if you keep them in the same room, keep them in separate areas and do not swap things in between them just yet. It’s too soon based on what you have stated. The new bun may have left his scent somewhere in the space you let them free roam in. Bambi smells it and she appears not to be happy about it- hence her reacting to you in a negative way in the free roam space. Yes, they will get used to each other’s smell. But don’t do any type of bonding stuff until they can calmly lay next to each other on each side of the separation area. Once they do, and have been for a little while, you need to have a neutral area- one where neither has ANY of their smell- and introduce them in that area- slowly. Bambi sounds a little more aggressive and that is okay. It just lets you know you need to take this very slow and cautiously. If you get to the point of neutral space, you need to sit with them- do not leave them alone- and do a short session. Even if it is going perfectly, don’t let it go on long enough until the perfection fades away. One good fight can ruin any chances of them bonding...ever.
Remember these guys are still young and growing mentally. Don’t rush the process or it will be a huge fail (based on what you have said so far). Also, be mentally prepared to house both of them separate forever if need be. I have 2- sets of bonded pairs and a solo bun. The solo bun can lay next to any of them with a separation and everyone is happy. If I remove the separation- not good. And it’s been this way for a year or more. They actually seem to look forward to seeing each other on the other side of the pen too so it just blows my mind. Also, the solo bun can mingle freely with the male bun in each set but I cannot allow the female bun in each set to be freely with her. I swear they would eat her! Also the 2 sets cannot all hang together. The 2 males can. There is a lot of shuffling that goes on in my house LOL but I learned a long time ago that I will need separate living spaces permanently and that’s what I have. They all have free roam space. One set free roams downstairs and the other set free roams upstairs. No one gets the stairs themselves! The solo bun has her own space but is a 3 pound dwarf lionhead so she is frequently carried around or sitting with one of us somewhere. She gets free roam time in any part of the house and I just put a pair up for a little while. At night, they all go to their respective areas- no one free roams at night.
I have 2 daughters, 5 bunnies, 2 cats and a fish. I swear I feel like I have 9 children! The fish is cool. LOL. All the bunnies are fine with the cats and the cats with them. I just play mediator!
Good luck!