I believe Dr Tim states, if ammonia or nitrite get above 5 ppm, to do a water change to get them low. 2 ppm shouldn't be a problem. I used the bottled bacteria as well and I was good to go within a week.
One thing to remember is a bare bottom tank takes longer to cycle than a tank with sand.
One thing that makes me nervous about bottled bacteria this time of year is the cold. If the bacteria freeze they die. I doubt that is the issue but it's a concern I have with bacteria in winter.
All in all I would say just give it some more time. I've read in various forums where people will be stuck in a cycle then everything starts dropping quick.