Install:
brew install homebrew/php/wp-cli
Upgrade:
brew upgrade wp-cli
Check version
wp --info
PHP not set to MAMP. which php
to check then edit zshrc path something like this
PATH=~/git-home/bin:/Applications/MAMP/bin/php/php5.6.10/bin/:/Applications/MAMP/bin/php/php5.6.10/:/Applications/MAMP/Library/bin:$PATH:
wpc [sitename] && cd [sitename]
wp core multisite-install --title="PHP 5.6.10" --admin_user="root" --admin_password="pw" --admin_email="zackary.allnutt@gmail.com"