I am a South African with a Schengen Visa and visiting Poland as my country of entry. Can I then travel on to Romania. I can't clearly find out if Romania is Schengen or not.
You can enter Romania on a Schengen visa IF it is a multiple entry Schengen visa.
From the Romanian Ministry of Foreign Affairs
Categories of third-state nationals also exempt from the requirement to be in possession of a Romanian short-stay visa are:
The holders of Schengen visas with two or multiple entries, national visas or residence permits issued by Schengen Member States.