Does Unlocking bootloader affect network lock?
No, the bootloader has no bearing on a SIM/network lock. The HTCdev site explicitly states this on the bootloader unlock page, in fact:


  Please note that unlocking your bootloader does not mean that you will
  be able to unlock the SIM lock. Unlocking your SIM lock is at the
  discretion of your operator/carrier and is not part of the bootloader
  unlocking scope.


The reverse is also true, but the main point is that the two concepts are unrelated.