It's great to see that FICO score rising, but you still have a little rebuilding to do. A mid FICO score is about 723 (give or take, and depending on who you talk to).
And, there are lots of folks who won't take you on with a BK reporting no matter what your FICO scores are. Here's a thread about BK friendly cards that may be helpful.
Do you have any closed accounts that are on your CR? Anything from before your BK? That will be helpful to know.
I'll have to second what others have said about waiting six months before app'ing for your next card. It'll definitely work in your favor. Right now most revolving accounts that would approve you will not be keeper cards, you'll want to pass those up. And keep rebuilding - take care of anything on your reports that's holding your score down.
If you post on this concern again in about five months; your score will be higher and you'll be ready to app for your next card. Your AAofA will be higher. And you'll be more likely to be approved for a long-term "keeper" card. A second card at this point is not likely to yield you any FICO points, btw. Your biggest FICO gain is when you open your first revolving bank account (your BofA secured card did that). At this point, again, you'll want just a little age before adding another inquiry and a new account. Let's see six months from opening your BofA puts you at this coming September. So hold that goal in your mind - something like, "After Labor Day, I'll want to be looking at adding another card. What can I do to keep rebuilding so I look darn good at that point? And which cards am I keeping my eye on for the next few months to see if I really really like em?"
Just puttin' syrup on something, don't make it pancakes.