Omeprazole is it used for gas bubbles as well as heartburn?

Gas bubbles sounds like a minor issue. Gas-X an OTC medication containing simethicone works well for me. Take as directed. You haven't given enough detail. Is it chronic? What do you suspect the cause is?
I'm not a physician. I hope you're feeling better very soon.

What is omeprazole?
Omeprazole is used to treat excess stomach acid in conditions such as non cancerous stomach ulcers, gastroesophageal reflux disease (GERD), active duodenal ulcer, Zollinger-Ellison syndrome and erosive esophagitis. Omeprazole works by blocking gastric acid production and is from the group of medicines called proton pump inhibitors.

Omeprazole may also be given together with antibiotics to treat gastric ulcer caused by infection with Helicobacter pylori (H. pylori).

Over-the-counter (OTC) omeprazole is used in adults to help control heartburn that occurs 2 or more days per week. The OTC brand must be taken as a course on a regular basis for 14 days in a row.

Source and more info: https://www.drugs.com/omeprazole.html#uses