They're public but the agenda isn't. We don't know what deal he and Putin are striking here and how that affects the Greek people. Yet Tsipras is happy to air any EU dirty laundry, but his dealings with the man waging war on Europe and murdering Ukrainian civilians? Total obedience and a commitment to secrecy.
Putin is slaughtering European civilians wholesale and has racked up thousands of dead in Ukraine and is under EU sanctions for it. Any deal with him under the guise of 'saving Europe' is tasteless at best, and treasonous at worst. Not to mention, he doesn't have this kind of money. Greece is 300+bn euros in the hole as of today. Russia's economy is shrinking at 2-4% per quarter right now and burning through its reserve trying to keep things running.
http://www.bbc.com/news/world-europe-32214140