You really need to try and keep them together for longer than a few minutes when bonding, pick a day when you can spend time with them to be able keep an eye on them. I would personally use the bathroom floor, give them a pile of hay to occupy them and then see what happens.
Leave them together and hopefully they will start to settle and become more comfortable with each other. Once you feel there confident that there is no aggression involved you can then try moving them into Molly's space. You may need to leave them in the bathroom overnight, or for a couple of days. Some lucky people have bunnies that will bond instantly but more often than not bonding is not a quick fix, you need to allow yourself and them some time.