I have been considering getting a credit card to earn BJ's rewards. Do you think their card is worth it or is there a better option to earn rewards?

There are almost always better alternatives to using a store card. In this case you can earn rewards without their credit card. They have a customer loyalty program called BJ's Perks. Membership in this program isn't free; it costs $100. But a basic membership will cost at least half that and probably a little more depending on any promotions they may be running. Each of their credit cards also have membership fees of up to $100 depending on the credit card you receive, so having their credit card won't save you any money in that respect. Their perks rewards program allows members to earn 2%. Their credit card offers 3% rewards. However, if you use their BJ's Perks Rewards membership combined with a card with rotating 5% categories, that would be 7%. So it is like double dipping in the reward pool.