Thank you for your question and for posting the pdf of the page in question.
The foreign language characters for Greek are to be found in World Braille Usage which can be downloaded for free at http://www.perkins.org/assets/downloads/worldbrailleusage/world-braille-usage-third-edition.pdf if you don't have a copy. I would use the Greek (International) table on pages 185-187 because of the accented characters and breath marks. There are no contractions used in International Greek.
In terms of Formats, it looks to me like the Greek is in bold, which I would retain to distinguish it from the English. Also, the Greek letters and breath marks should be listed on the Special Symbols Page.
Your sample also has the breath marks ῾ spiritus asper (rough breathing) (dots 125) and ᾿ spiritus lenis (smooth breathing) (dots 356). These signs are placed before the vowel to which they apply.
Please let me know if you have any other questions.
Vice-Chair, Foreign Language Committee