Preview at WWDC likely in June, followed by September launch.
JCPenney Testing Apple Pay Support for Store Cards, Nationwide Rollout Coming in Spring 2016
Customers with a JCPenney charge card receive a notice about the Texas pilot program when attempting to add a JCPenney card to Apple Pay using the Wallet app. The notification also includes details about the full launch of the JCPenney Apple Pay service.
Apple Pay support for store credit cards is a new feature, introduced alongside iOS 9 but announced at this year's Worldwide Developers Conference in June. Thus far, Kohl's is the only major retailer that currently allows its store cards to be added to Apple Pay, but both Kohl's and JCPenney have been touted as the two major partners for the feature.
iOS 9 also brought Apple Pay support for in-store loyalty cards, allowing customers to add their rewards cards to the Wallet app to further cut down on the number of physical cards that must be carried. Walgreens is the first retailer to support the Apple Pay rewards program.