Even with your own scanning electron microscope, identifying the specific species of whatever was grown would be impossible without extracting, purifying, and sequencing the nucleic acid found in the tea. Bacteria aren't all the same, and just because it's shaped like a "rod" doesn't mean anything for positive identification. There can be as many as 50,000 different species of bacteria in a single gram of field soil! The diversity is dizzying because a different gram of soil somewhere may only have a few hundred species overlapping with the other. In all cases some of these bacteria are beneficial in some way, some will be innocuous, some will compete with a throw off the balance of nitrifiers in your soil causing N issues, and some may be deadly human pathogens. Which species are we growing in our tanks and bottles?
Bacteria and other creatures who find themselves floating around in an aqueous solution in a bottle obviously find themselves in a radically different environment than your typical rhizosphere. It's obvious that these environmental changes will favor some species over others as many will find the new environment even better than soil, while other species do not and competition ensues. So you'll get a different distribution of species than the raw compost starting material. Is that good or bad? Luck of the draw I guess?
There are hundreds of bacteria inoculant preparations currently licensed in the world. For example I think species from the Rhizobium genus have been available as an inoculant for a long time now. But the way these inoculants are cultured and prepared has no connection to compost teas prepared under uncontrolled conditions and starting material. This is why science can't even ask your question as a hypothesis, because to ask "do compost teas offer real benefits" assumes that compost teas would have the same bacterial composition, and we know that's not true.
What we do know is that fermented teas can often contain more plant available nutrients (NPK) than that contained in the original compost or other starting material. Is this a good thing? It depends on the goal of organic agriculture in general, and these days I honestly don't know what that is anymore. Regardless of whether the salts you use come from a bottle or a tank of brewing poop, the use of readily available salts has severely impacted soil tilth and CEC through the continuing loss of stable carbon. These salts are also highly mobile in soil, and raise the nutrient levels of whatever body of water is nearby causing eutrophication and the end to someone's favorite fishing spot. Haven't we learned our lesson yet?
Anyway, I did find this Korean study that is an interesting read: Effect of Aerated Compost Tea on the Growth Promotion of Lettuce, Soybean, and Sweet Corn in Organic Cultivation
