It is clear to me how to link BTC addresses for distribution rounds but what about Byteball addresses? Do I have to collect my newly acquired byteball into my linked addy or do they get funded automatically and I don't have do anything (except controlling the keys)?

The distribution rules:

BTC to bytes: 1 BTC of proven balance gives you 62.5 MB (0.0625 GB)
BTC to blackbytes: 1 BTC of proven balance gives you 2.1111 * 62.5 million blackbytes (money supply of blackbytes is 2.1111 times more than that of bytes)
Bytes to bytes: 1 byte on any Byteball address gives you 0.1 new bytes
Bytes to blackbytes: 1 byte on linked Byteball address gives you 0.21111 blackbytes