My girlfriend has two bumps on the underside of her tounge that are irritated and a white tent to her tounge what could be the cause of this?

Various causes. Two bumps on the underside of the tongue should be evaluated by a dental professional immediately to properly diagnose the condition. Causes could be medications, foods or infection.
Salivary glands. The 2 bumps are probably her sub-lingual salivary glands --normal. Irritation often occurs from the underside of tongue rubbing over the lower teeth when tongue is extended , as in kissing. The white tint could be temporary from food, or a fungal infection. She can stick her tongue out all the way then pull it back using her top teeth to try to scrape away any buildup. May need to ckeck @ dentist.