There’s no conflict with the touchscreen I’m aware of and, unfortunately, no way for the Pi to “see” the Speaker pHAT in any meaningful way. i2s audio is write-only- a software configuration that outputs a digital audio signal on the right pins. The Pi side of things doesn’t care if there’s a DAC even connected!
My guess is soldering- did you use a hammer header, or solder? Could you post a photo of your pHAT?