grep --include=\*.php --include=\*.inc --include=\*.css --include=\*.js --include=\*.html --exclude-dir=vendor

to make as an aliases, add to ~/.bashrc

alias grepPHP='grep --include=\*.php --include=\*.inc --include=\*.css --include=\*.js --include=\*.html --exclude-dir=vendor'

to use:

grepPHP someFunction -r