The bus seems well built, and it rolls (unlike some other bus-shaped learning toys), but the phonics sounds are almost unintelligible for two reasons. First, the speakers are poor quality and the sounds come out garbled. Second, the designers chose to get fancy and add multiple silly voices to each track, so when it says "A says, ah", you get one silly voice for "A" and a completely different voice for "ah", making it hard to follow, and the silly voices plus bad speakers pretty much make the phonics sounds nonsense.
If you just want something to keep a toddler engaged, this definitely fits the bill. It has a huge variety of sounds and lots of fun buttons. I personally resent that the toy calls you back to push buttons if you leave it alone for a few seconds, but maybe that's a plus for some people. I would rate this toy as obnoxious, which would have been fine with me if it were actually exposing my kid to phonics sounds.