I agree with Denny as to finish of fermentation - don't rely on the bubbles; but, you can pretty well rely on the bubbles as evidence that fermentation is continuing. However, off-gassing due to temperature change or disturbing the fermenter post-ferment can occur, which isn't the same as a steady bubbling of active fermentation.
All of that said, my lagers finish typically in a week to 10 days (with a very healthy pitch of yeast, of course), but occasionally I have an outlier that takes a couple weeks. I use a Tilt hydrometer, so I can always monitor changing gravity and stabilized gravity. I don't typically spund, but with the Tilt, it makes it easier to follow when you are approaching the expected final gravity.