Pre-rinse faucets with a riser may include a wall bracket to help use the wall for added stability. Pre-rinse faucets without a riser will generally not include or need a wall bracket.
If your unit comes with a bracket, or you plan on adding one, the bracket can be installed at whatever height you prefer, but to be effective it should be placed far enough above the base so as to inhibit movement to the riser – placing too close to the base may make it ineffective.
If you intend to use a wall bracket, consider potential concerns with the installation location, such as shelving or windows behind the faucet, that might limit where you can place the bracket.