I regard fizzing as a sign of feeding Tench and,more often than not,I’ll get one or two. Streams of bubbles are different and often the bottom.
You need a Tench venue with lilies to really prove it to yourself that the fizzing is feeding Tench. Fish as close as you dare to the lilies and feed to the edge of them. The Tench will come out from under the lilies and fizz exactly where you’ve fed and you can,almost,guarantee you’ll get one. They will be feeding on what you’ve fed otherwise they’d be fizzing all around the lilies. Catching in open water can be much more frustrating,waiting for the fizzing fish to find your feed,especially if there’s a lot of natural feed in the water.
So. Fizzing where you’ve fed is fish feeding on what you’ve put in. Fizzing elsewhere is fish feeding on there way to where you’ve fed

Bream are different. I normally rely on a bit of watercraft and,hopefully,spotting one or two fish roll. On one weed free gravel pit if fish I often catch in an area where I see single bubbles coming up over a decent area in open water. It’s not guaranteed but I regard it as a reliable sign that something is causing the bubbles to come up and it’s possibly Bream. What I do,weather permitting,is look to see what’s happening over my feed once I’ve started catching and those same single bubbles will concentrated in the area I’m fishing......sometimes.
Bubbles might well be fish filter feeding on natural feed but unless they are really wised up you will still catch on what you are offering as long as you’re presentation is good. I feed pellets and corn when Bream fishing but still get most of my fish on worm?
So stay positive,bubbles are a good thing?