I just don't understand.
I the past 2 years I have reestablished my credit. I have 2 car loans and a new mortgage. My debt to income ratio is excellent. Yet the only credit card I can get approved for has a credit line of $500.

What can I do?

That's a start.

Use it wisely for everyday things never exceed 30% of your credit limit in any given month and pay in full before the due date.

In no time you will be getting offers for other better cards.

Trust me, I went through the same thing over 7-years ago.

Be grateful that you at least have ONE credit card and
just keep paying cash for whatever you can. The bankruptcy
will be on your reports for 7 to 10 years

No one can give you a solid answer except someone in credit like your bank who has your credit bureau. A lot of factors involved. Did you try Capital One? If you have the money you can get a secured visa or mastercard.