I have confirmed this as Utricularia australis, as there isn't any other species that it could be, based on distribution patterns. The other two yellow-flowered bladderworts are either predominantly coastal, or else northern NSW. But the ID is 'confirmed' with reservations. According to PlantNet, In U. australis, the lower lip should have brown lines and spots (example: sighting 4359423), but barely present here, and be much larger than the upper lip (FloraVic).
Interesting snippet: A specimen of U. australis was collected from the Bredbo River in 1890
Corrected to Utricularia gibba. Correction based on: the Upper lip of corolla being larger than the lower lip: and the spur is longer than the lower lip of corolla. In U. australis, it is the opposite: the lower lip is larger, and the spur is shorter).
there should be no confusion between U. biloba and U. gibba. U biloba has blue flowers, U gibba has yellow flowers. this is a bit annoying: my entry for U. gibba got changed to U. biloba.