From the said conversation in Episode 4 and what we know of Episodes 1-3 we know that <PERSON> and <PERSON> know that <PERSON> is a Jedi. Or more was. What is more is that the Jedi were officially discredited and executed in Episode 3.
When <PERSON> met <PERSON> that one went off to find his mother (who was <PERSON> step mother) and rescue her alone from a place where not even a full group of armed men managed to get her from and succeeded easily, bringing her back dead though.
What they know of the Jedi is most likely whatever the Seante put out there in addition from what they saw from <PERSON>. They know that the Jedi are fugitives and if <PERSON> comes even remotely after his father he will be a fugitive and more so he will move out of their lives forever. As both <PERSON> and <PERSON> are very fond of <PERSON> and don't want him out of their lives they have a dislike for that especially <PERSON> who probably didn't even forgive <PERSON> father for leaving the boy alone.
If <PERSON> knows that <PERSON> is <PERSON> the chances are.....low very low. First off when <PERSON> brought the baby he thought <PERSON> was dead. 503
Probably later on he learned the truth though BUT admitting it or not he is VERY ashamed of what happeend to his former pupil at that time. One can see it quite clearly in episode 3 that he is hurt and ashamed at the same time. About what happened to his pupil and of his failure to teach him correctly, so that this all could have been avoided. With that in mind it is very unlikely that months or years after he came to <PERSON> and said "Oh and the gruelsome executor the Emperor has.....is <PERSON> father". Even taken from the non emotional Jedi perspective it wouldn't have made much sense as in the worst case it would have made <PERSON> unsure if it was wise/save to still keep the baby with them or not. And wouldn't have served any further purpose there aside from that. So very unlikely. 865