In terms of knowing when it's safe to bottle I would wait another week or so and take another reading, possibly repeating this once more (wait another week and another reading) if it is stable at 1.009 it's probably safe. I have not used this yeast nor, for that matter any brett yet so I don't know but it seems like 3 or 4 weeks of stable readings are pretty safe. It probably won't hurt to add fresh yeast at bottling, I think a general rule of thumb is .25 packet of something like us05.