Nothing will happen if you get rejected, it pays to try
It didn't say when you were instant approved how much your credit line was for? Or were you not instantly approved?
+1, might as well go for it.
I applied and then got distracted with something, and when I came back to screen it was back to the Alaska Airlines main page, called up the Spanish line, and the rep said that I was approved for a credit line of 5k bh.