Clearly stated here that 'goto' instruction will affect the first 9 bits in the program memory, branching for more than 9 bits will need to write into bit 9 and 10 of program counter, via STATUS register bit 5 and 6. This is also known as paging.
Note: Because PC<8> is cleared in the CALL
instruction or any modified PCL instruction,
all subroutine calls or computed
jumps are limited to the first 256 locations
of any program memory page (512 words
long).
Yes. As long as the subroutine is in the first 256 words. When a CALL is executed, bit 8 of the program counter is cleared (refer to the datasheet under instruction set).