Your Templates are stored the same place they always have been. Note that when you go to save one, the dialog box indicates the name of the folder; My Templates.
Perhaps the problem is that you can't find My Tempaltes in ML. They are still in your User Library, Application Support, iWork, Pages, Templates, My Templates. But, getting to your User Library is different in ML. On the Finder Menu line Choose Go and hold down the Option key to display Library as one of the choices to Go to.