How does a surveillance balloon get the collected data back to where it is analyzed and used? I suspect the data is relayed by satellite (unless there are collection sites within the US). Which Chinese satellites are able to cover the US?
Almost certainly by satellite. To wit, every iPhone 14 now has an emergency text feature that works via satellite-- you could potentially just use one of those and send everything base64 encoded.
It releases smaller data balloons.
Most of China' communication satellites are in GEO over Asia, but they do have plenty of remote sensing and ELINT birds that fly over the US.
I assume China has global coverage, as the US does?