Details for the Chase DISNEY Visa perks currently being offered (such as booking early events) are posted over on the F&W thread on the restaurant board.
Details for the Chase Visa Lounge (which is what I assume you are looking for) don't usually get reported until the festival begins.
Going on past experiences, the Chase Visa Lounge is open to all Chase Visa cardmembers (up to 6 guests per cardholder) and the perks are: drinks, phone charging, restrooms, a place to relax, etc...
However, the ETTB concert wristbands are a perk reserved for Chase DISNEY Visa cardmembers only and only on specific days. For example, wristbands were only available for 1 out of the 3 days Boyz II Men was performing one year. Therefore, if a particular concert is an absolute must-do on your list, I would book a FP+ or dining package. Otherwise, if you meet the criteria for wristbands, the lounge opens at 11 am.
Also, there is no special seating for Illuminations (like there is for ETTB), just a roped-off area for guests to stand or sit on the ground. They used to give wristbands for this, but I don't think they did last year. Guests just showed up and presented their card for admittance.