A little affection after a month with a feral is not too bad. Does he follow you around or end up in the same room with you over time (even if he runs away when you move)?Within the month+ I've had him, he's come up to me for affection maybe 3 times. Would like to see more, but this is definitely better than 0!
One of my guys was sort-of-feral and super shy. After a couple of weeks, I could tell he wanted affection/company, but was just not trusting enough. Even after a year, he sometimes runs away if something seems odd to him - but now he comes by for pets all the time, climbs into bed when the other cat lets him and is playful as anything. Build his confidence with play - it took me a while to find out that he LOVES the mouse toy from Da Bird - after I got him playing with that until he was panting and exhausted, he really came out of his shell. I really think that his trust and confidence flowed out of the intense play sessions.