How to redeem reward points on RBL Bank credit card?

On the add-on card: yes, the primary cardholder is fully liable for all spends on the add-on. There is no separate credit limit or statement. So only issue it to someone you trust absolutely — spouse, parents. Not friends, not siblings you have money disputes with.

I had the same dilemma. The way I decided was: list down my top 3 monthly spend categories, calculate the rewards on each card, and pick whichever gives the highest cashback on MY pattern. Generic 'best card' lists are useless for personal decisions.