When Cirie said that she couldn't trust anyone in the Jonathan / Eliza / Ami / Yau alliance, what she was really saying was how she ranked herself against each in terms of smarts and IQ. Ciries knows that she is smarter than James and Parvati and is probably on a par with Ozzy and Amanda. She has a better chance of fooling them than ever being able to outsmart anyone in the other group. She knows that she can't pull off as many lies with the smart alliance and her assessment is that Yau is the smartest of the bunch.
The "trustworthiness" of the smart alliance had nothing to do with it.
That makes sense. There’s no flying under the radar for her this go round.