Bubbles under IPad Screen

You would be best advised to visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to assess your iPad - and you can explore your available options:

Genius Bar Reservation and Apple Support Options - Apple

As mentioned by y_p_w, if your iPad is within its one year limited warranty, the defect (if confirmed) should be covered.

If you have benefit of an active AppleCare plan, an additional cost option that had to be purchased within 60-days of initial purchase of your iPad, any defects or non-warranty claims will be covered.

It should be covered under warranty. The glass is laid over the LCD display and it can delaminate or there could have been a defect. Such a warranty service would only be in the form of a complete replacement where you would need a backup to restore to the replacement iPad.