Turns out Mac (Mavericks or Yosemite) doesn't have ANT installed as part of their distro. Once I downloaded ANT 1.9.4 from the Apache website, then added its path to my .bash_profile, Tomcat started right up and displayed the friendly landing page.
Hope anyone struggling to get Tomcat up and running on MacOS 10.9 or 10.10 finds this helpful.
Regards,
Ron