Jared
You cannot, repeat, CAN NOT bowl for cash under the new rule.
A youth bowler may enter an adult singles league/tournament offering cash of any amount as long as he/she signs USBC's waiver, waiving the rights to the cash that might be won, before the event begins. If the tournament directors are willing to convert the cash to scholarship dollars to be deposited in SMART, and mark that on the waiver, that would be allowable, up to any dollar amount.
Youth bowlers are now allowed to win bowling equipment, gift certificates, apparel, etc. up to $500 in any event.
Hope this helps