I'm extremely hesitant about bonding a babyrabbit to an adult because of some horror stories and my personalexperience. When (and if) the baby reaches the teen stage, which mostrabbits will hit, the adult rabbit may be challenged for dominence andyou could be in for trouble.
Someone I know bonded a baby rabbit to their adult and she came homeone day months after bonding them together to find that the younger onehad challenged for dominence and both were badly hurt. One had piecesof her tail and ears missing and the other had cuts on his body.
I also had 2 rabbits bonded from about 4 months of age until about 10months. Both were fixed but one day out of the blue they startedfighting in their hutch. They both escaped harm only because I happenedto have the day off from school and separated them immediately but hadI been at school, I would have hated to know what I'd have found when Icame home.
I'm not saying don't bond a rabbits at an early age, just do not housethem together or let them out together unsupervised until at least ayear. After a year, the chance of the teen years being an issue is slimsince most would have hit it already.
Also remember that an adult may get along with a baby but when thatbaby grows up, the adult may have serious issues with the other rabbitor the young one may have serious issues with an older rabbit.
Some rabbits are also very anti-social when it comes to other rabbits.One of my males is simply unbondable. I've had about 5 other rabbitsaround him and all of them he tries to kill. He hates other rabbits,young or old, male or female. I've even been attack by him just forsmelling like another rabbit (he's normally a very docile animal).
But I did get a baby last summer and she and my other male are to bebonded soon now that she's almost a year old and both are fixed.
Just keep in mind that instead of getting that match made in heavenlike you dream of, you may get a pair of mortal enemies that have to behoused separately and then you have less individual time for each.That's why I suggest adopting an older rabbit and taking your rabbit tovisit them to see how they react.
Now that I've made all the bad points very clear, there are just asmany good points. A pair is fun to watch and often their interactionwith you will not change.
If your originial rabbit is fine with you, chances are that will notchange for the most part. If you're concerned about how the new rabbitwill behave with you, I'd suggest taking a month before attempting tobond the rabbits and use that time to bond with the new one. I've hadmy doe for 6.5 months and I've spent hours handling her and socializingher to make sure she's ok with me before I bond her to my male becauseit's a lot harder to bond to it once it's in a pair.
But good luck and I hope you find a good rabbit to bond her to!