I can credit all the muscle development in my upper back and arms to the pole/yoga combo, I catch myself staring in the mirror all the time. :)
There's a great DVD by Rodney Yee, "Yoga Burn," where you do a full hour but go very, very slowly, almost painfully slow. So yeah, maybe you're just doing 3 down dogs, but you're holding them for minutes a time! That's a great way to use yoga for strength. He has a Core Cross Train one that I like a lot too, though I haven't done it in a while (ever since the weather got nice, I've been neglecting my DVDs - but not like I've been out exercising either! haha).
Oh and if budget and equipment is a worry, go to your pantry! Water bottles, sacks of flour or sugar, and canned goods can be used as weights. You'll feel like an idiot curling milk jugs in your living room but it works. :) And you can often use a beach towel much like a resistance band, for example to loop around your pole and lean back and do rows.
Just be careful how much strength + pole you do in a row, you can overwork your muscles if you keep working the same groups with the same movements. Look on the internet for exercises that work particular muscles or muscle groups, and switch it up pretty frequently, so you're not just doing the same movements every time and giving yourself repetitive motion injuries.