Seems there is a issue when you install the xcode developers tools from the Apple app store, it does install the command line tools, if you want to run apps like homebrew etc. You do not need the command line tools to install homebrew, but you do need the command line tools.
To install the command line xcode tools. You need to start up xcode, the go file > preferences > downloads and the click on install Command line tools. Its that simple. Just sit back, wait for about 100mb to download and install.