I spend about six hours in the car each week so it's fun to listen to the Survivor and Amazing race podcasts. I listened to the "Rob has a podcast" (former Survivor Rob Cestrinino) segment that had Richard Hatch and Parvarti on it just yesterday. I heard Parvarti say that about Tasha/Spencer not having the alliance. I really thought they did too. I think it would be awesome to have both Spencer & Tony as the finalists to hear their arguments for why they should win. As you said, Spencer has came through every time he had to while Tony pretty well controlled most of the game albeit not very subtlely.
I'm hope Spenser wins as well, not so much because of the underdog thing but because he has been brilliant when he needed to be. He's planted seeds to get the vote away from him and won crucial immunities to save himself. He has made it to final 4 and never had a true alliance. If you listen to Tasha's interview with Parvarti after her boot, he and Tasha did not even have an alliance.
It's certainly been a fun season to watch though. Tony has played really hard but he had numbers on his side the whole time so really he played harder than he even needed to. It will be an interesting finale for sure.