TL;DR: A rather forgettable card to have in your wallet, however its essentially free with a POSB savings account. If you do make it a point to remember the specific benefits (and you don't already have a credit card with better perks) you can get the most/more out of this card so why not I guess?
It was issued to me for having a POSB savings account so I didn't have to do anything to get it. It's an upgrade on its predecessor (debit card for POSB Savings account) as it carries the Passion branding now and has more perks.
[Perks & Promotions]
On a daily basis, they do carry a decent amount of rebates from certain stores and promos with certain partners. However, what I've realistically benefitted from would probably be the small discount off movie tickets (not exclusive to this card but to DBS/POSB) and rebates on certain purchases (groceries/Cathay) - sometimes not intentionally I must add.
If you do actually remember or make it a point to, the card offers 1-for-1 deals on the 10th of every month to the numerous attractions in Sentosa, and a couple outside. 1 for 1 tickets at Cathay on the same date as well.
I believe there're no fees on the card at all.