There were no tea party protests during the end of the bush presidency for a few reasons; only 1 of those is blind partisanship, and that is only on the part of a few.
A bigger reason is we were in the midst of a presidential election, and the "crisis" seemed to hit most americans out of nowhere. It took a little while to get bearings. You also didn't have a natural date sitting around for the protesters to rally around like April 15.
But I also want top address whether or not the teaparties were "grassroots" or astroturf.
Originally, and for many they were grassroots. The idea behind them is good. Protest the fed, bailouts, income tax and bank stupidity. Thats a legitimate political viewpoint held by millions of rational americans.
But sadly, the GOP and Fox News (and the rest of mainstream, partisan establishment) tried and in some cases successfully co-opted yet another movement.
Early on the 15th I recieved an email from Michael Steal promoting sending teabags to democrats in washington as a way to voice dissatisfaction - and even though I knew it was a viral email I replied and said "the GOP is very much complicit in what happened, I ought to be sending the tea to you".
I then went to the local teaparty and saw everything from gun rights groups, to pro-life speakers taking the stage to signs that called Obama the anti-Christ. And it occured to me that these people didnt even know what they were protesting. Some had an idea, but on the whole it became a cheap affair.
But you need to be careful throwing the idea around that this is merely political posturing, partisan hackery and party level planning. Yea there is a lot of that wrapped in a big ball of confusion, but somewhere in there exists some really ticked off americans and rightfully so.