Sure, you just need to access the bank in the same way and withdraw the points. When you pay someone, the forum takes 10% so would need to deposit 10bn plus 100million.
At the bottom of the bank it wil say how much your interest payment will be and when...
If you look at forum menu above, you will notice one that says "vbPlaza Menu", click on that and then click on "bank" and deposit your 100BN points. You will get interest, probably 20 million every 48 hours, or something in that region, perhaps a lot more, I can't remember exactly.
Great stuff & good luck. I've got a few points on Trout to win, but I think it's going to be a good hard fight, both young guys without a loss and with a belt to protect, I can see it being really good