No, you cannot use your Zales Credit Card everywhere. You can only use this card at Zales and their affiliates.
The only store cards that can be used anywhere are known as open-loop cards and belong to a major credit card network that grants them worldwide acceptance.
Here's where you can use the Zales Credit Card:
At Zales stores and Zales.com
At Zales Outlet stores and ZalesOutlet.com
At Gordon's stores and their website
At Banter by Piercing Pagoda stores and their website
Zales Credit Card is designed as a financing option for Zales purchases. You get different payment plans (0% - 16.99% for 6 - 36 months), depending on how much you spend.
Bear in mind that the rates you get are deferred interest rates, so if you don't pay in full by the end of your introductory term, an APR of 29.99% applies to your entire purchase. With regular 0% APR credit cards, your remaining balance starts accruing interest at the end of your introductory period.