On page 8 it states:
Each of the 16,777,216-bit banks is organized as 2,048 rows by 256 columns
And 11-bit = 2048 so the 11-bit Address bus is sufficient to select any of the rows (I'm not saying it actually works like that).
But how do we select the columns?
We use the same 11-bit Address bus again. The rows and columns are not selected at once but separately and the separation is done in time. Note how there is a certain sequence to be observed when addressing the data!
Theoretically even a 1-bit (instead of 11-bit) address bus could be used to address any of the bits on a memory chip with the same capacity by sending the address information in a serial way, so one after the other. Yes, that would not be fast (it would be slow) but it can work.