I don’t like ion-item component, it’s very not flexible.
First: ion-item has wrong name, ion-item is like poor md-input-container. You must use it for inputs/select/etc with labels.
Second: You not must use ion-item in ion-list, because you must use it for inputs in forms too, but your forms are not list usually 
Third: You can use ONLY ONE ion-input, ion-label and some another ionic components into ion-item, all another HTML will be ignored.
So this component is very poor and very usability. I hope, Ionic Team will fix it.
PS Sorry about my terrible English, but I think you can understand that I mean.