I am not an expert in any way with bonding, as I’m bonding two rabbits currently myself. But I may be able to give you some advice. First, my male bunny does the same thing with my three cats. They react the same way. I don’t really think cats know what the bunny is asking. I find that my bunnies are very similar to how my cats act with me. Bunnies can be very attached to their owners, so it’s normal if she is following you around. I honestly think she just really loves you. My male bunny hates tile floors but will try walking on it anyway just to follow me.

As far as bonding bunnies, have you done any prebonding? Pre bonding is VERY important as I learned that with my two. I had wrong information when I first got my second bunny, and did not know you had to do pre bonding before doing an any actual bonding session. Also I didn’t know if I missed it, but are they both fixed? And if they are fixed how long has it been?

First, your new bunny is probably aggressive because he’s scared. You’ve had him a month and you’re already putting him with a new bunny. That’s a lot of changes and he’s probably stressed out.
Second, are both bunnies fixed? If not, they need to remain completely separate until you get them both fixed. Bunnies don’t bond unless they have been fixed. Hormones cause a lot of issues, mainly aggression and being territorial.
IF they are both fixed, let him settle in for a good month without seeing your existing bunny. Let him get to learn the routine of the house and really just bond with you and feel comfortable overall. Then after a month, you can begin prebonding them by swapping them between each others enclosures. After prebonding you can begin bonding sessions for short periods of times in neutral territory (space neither bunny has been in).

Your girl bows her head to ask for grooms. This is typically a sign of dominance.