Tips on bonding?

I'd suggest giving him more time to adapt before trying to get him to step up. It sounds like the poor little guy has been through a lot in his short life so far, and I think the best thing you can do for him is to back off for a while. 

Look at the process as a series of little steps. First, the goal is to get him comfortable with you near his cage. Sit with him at whatever distance he is comfortable with, and talk gently, read, watch tv, or whatever. Reward him often when he is calm. Start moving gradually closer to him, but move back if it stresses him at all. You might need to stretch this out for weeks, or even months, depending on Apollo. The next step would be to get him to leave his cage on his own. Put a perch on the outside of his cage and leave the door open, when you can supervise. Put favorite treats around where he has to leave the cage to reach them. After he's comfortable with that, you can start offering things from your hand and start training the step up from there. 

We all want to start right away showering our birds with the love they deserve, and what I'm suggesting takes a whole lot of patience. But they have potential life spans of 30+ years, and if you can start things off right, at Apollo's own speed, you can have a wonderful bond in the long run. He's had a rougher start than most, and it might take him quite a while before you see progress.