In my experience group of friends are allowed. Last year I went there with a friend of mine, both as “single”, and they let us in. Have to say they know us since many years.
Other friends came and didn’t have any problem. The inf card is a nice to have but not strictly needed for what I know, especially if you have friends inside.
Cool - but what about single travellers that have been there before numerous times without issues? TBH I was not planning to go to valalta this year but it is good to know where my options lie within these weird corona times.
If they know you it won’t be a problem I believe. To be sure drop them a call and verify as the policy might change over time.
As I mentioned I /we never got a problems (I’ve been there as “single” with friends, as couple, and as couple with fiends). From time to time I heard of people not being allowed in but I don’t know the reason why.