I mean, there's a chance you'd get approved now as you may have satisfied their denial reason. Your "experience" however with that $6k line of credit is still only 2-3 months, so while you possess a limit > $5k, you haven't for very long, so they could still say you don't have much experience with it. Experience can be interpreted both ways, as either possessing it or in terms of time like how long you've had it.
I'd honestly give it 6 months [since denial]. You could even give it a little longer than that and allow your next Amex CLI (perhaps 3X) report, since that's in 3-4 months. That way they'd see you had 6 months experience with the $6k Amex limit and that your current Amex limit is even higher than that, as much as $18k depending on how your next CLI goes with them.
Have you tried the pre-qualify/approval? Chase would not open me for years (CO from a pre-Chase bank). Every couple of months I would try the offers. Nothing. Then just over a month ago, three popped up and I was in. Good luck!
And I was at 5/24 when I was approved.