I’m going to go through this section by section. You = Bold, Me = Not Bold. 

I know I would need to have separate cages/x-pens for the rabbits before they are fully bonded.  Just to confirm, these cages could in the same room, right?  I would also need neutral space for meetings, which could be my bedroom, as Dobby isn’t currently allowed in there at all.  I know I would have to start with a small part of the bedroom and then slow expand their space.

They can be in the same room just not close enough to “get at” each other through the cages/pens. You generally do bonding in smaller spaces and expand later on. You start neutral, then go semi-neutral, and then non-neutral. 

I also know I should start with short bonding sessions.  I am a little confused about what should be allowed when they aren’t in bonding sessions.  Is it OK if I let them both, separately, have time out in the living room to get some exercise?  Or do they need to stay in their cages when not in bonding sessions?  Right now Dobby gets to spend the mornings while I’m getting ready for work and the evenings and weekends in the living room, so staying in his cage would be a big change for him.

Well… Short sessions are debatable. It is generally recommended that you start off with shorter sessions and then increase them as time goes on. For rabbits that are really at odds shorter session are probably best. For rabbits with minimal aggression I would do longer sessions. They can have play time when you’re not bonding them, while you’re getting ready, etc… But you’re going to want to spend as much time as you can working with them and bonding. During the process it is likely they’ll get less play time because you’ll be spending some of that time bonding. 

Also, right now, Dobby gets to spend the day in the kitchen and bathroom.  If I cleaned the bathroom thoroughly, would it be OK to let the new bunny hang out in there during the day and let Dobby continue to hang out in the kitchen?The other option is to let the new bunny have a slightly larger space in my bedroom during the day and clean the bathroom thoroughly to get rid of Dobby’s smell in the hopes of making it a neutral space.  Would this be enough to make it a neutral space?  (The bathtub really won’t work b/c it has a sliding glass door and I wouldn’t be able to easily separate fights and such with that in the way.)  

Do you mean while you’re at work or out of the house? I don’t see why not as long as they’re separated/can’t fight. Either option seems fine to me. 

I’m assuming my semi-neutral space would be the living room, especially if they are both allowed to use it from the start to get some exercise.

Sounds good. 

Finally, if the bond doesn’t work, would they be able to share the living room as exercise space, albeit at different times?

I would give yourself the best chance of success. One of the ways you can do this is by taking Dobby on “Bunny Dates”. This is where you take him to rescues/shelters and have him meet bunnies until you find one that’s compatable with him. If you were to find yourself in a situation with two unbondable bunnies than you could definintely house them separatly and let them out separately. 

If you decide to bond one thing I REALLY suggest is starting a bonding thread here and make detailed posts about how things are going/issues your having etc… People can offer you advice and support as you go. It’s really helpful.