Soy butter was gross but sunbutter isn't bad - though - having myself never eaten peanut butter beyond the age of 1, I have zero clue what peanut butter tastes like. I do know that the smell wasn't repulsive, which I find peanut butter, so that was a plus.
My kids said it was positively nasty as PBJ.
Also, peanuts are not tree nuts. Peanuts are legumes. So if the school has issued a "tree nut free" call then you could very well be safe to bring peanuts. I'd call and ask. If nothing else, you might alert them to the fact that they've made an error. Many people have no idea that they're different. I"m asked all the time if I can eat walnuts and I can. Just not peanuts.
I also don't seem to have a problem with any other legume (beans/soy), except peas repulse me in exactly the same way that peanuts do, so I have no desire to test if I'm still allergic. As a baby I constantly vomited every time I ate peas and my mother thought I was just stubborn, so she kept giving them to me..