I will respond to my own question. Yes, you can keep on redeeming 2,500 points against $25 charge (Southwest GC), and drain all of your points down. So you will essentially get $500 sign up bonus + $90 for spending $4,500 on the card.
One other thing I learned, if your significant other gets the same card, they can transfer all miles to you. It is done instantly online and their miles show up in your account instantly. So you can redeem more miles against that same charge of $25.
Long story short, I got to redeem 47 times, in 2,500 mile increments against the same $25 charge.
Cheers,
PedroNY