On mining pools all miners get rewarded with the analogous CPU they have used.
I don't know exactly how many satoshis will be generated on every block after 2100 but I know they will be very few. Imagine splitting 1 satoshi. How? Will the bitcoin community create the nakamotos?
1 satoshi = 1000 nakamotos for example. Too dumb question, tho, since we can't know a damn thing about that era. Some say that life will end after 2100 due to loss of natural supplies.
Miners do not profit from mining the default block reward alone. Along with the mined blocks are the transaction fees which in the future may seem sufficient for the miners to have profit and continue mining. So definitely mining pools will still exist after 2100 to mine for the transaction fees.