@noneck DOT committing to release their bike lane data is one great result of that forum. When I made that comment someone sitting close by let me know that bike lane vectors are also available from the DCP's street data. They are aparently a layer or attribute on certain streets and this dataset is updated every 3 months, I haven't gotten a chance to actually find this data yet though.
Pop Chart Lab also made a bike lane only map of NYC that you can buy prints of. I actually own this print, and I'm pretty sure the data is from 2013.