Poker doesn't earn comps very fast since it's less profitable for the casino than traditional table games (though hopefully you also lose less money). I believe Borgata has a pretty straightforward comp deal in terms of poker, a certain amount of comp dollars per hour played. For free rooms, a good estimate is roughly what your average comp dollar earnings per trip are -- in my experience when you start to be around $40 comp dollars earned per trip you can expect to get most Friday nights available as a comp. I'm pretty sure that level would be hard to reach just playing poker, especially at the lower-limit tables.

However, even playing the amount you do, you should have a discounted room rate showing up in your account, so it may be worth just paying for the room if it's worth it to you; if you book in advance and avoid holiday weekends the discounted rates can be quite reasonable.

Of course, the other way to get a comped room is to earn more comp dollars per trip, which probably means playing table games -- but of course there is an expected loss to the house for every dollar gambled there, and the house aims to give you back less in comps than you are expected over time to lose at the tables.