<div class="slds-form-element__control">
    <ui:inputPhone class="slds-input" placeholder="{!Phone}" change='c.save'>
    </ui:inputPhone>
    <span id="{!'thisInput'+i}"></span>
</div>

save: function(cmp, evt){
  var targetCmp = evt.getSource();
  var val = targetCmp.get('v.value');
  var inputId = targetCmp.getElement().nextSibling.nextSibling.id;

  console.log(value);
  console.log(inputId);
}

<!--render facet: 0000:00;a-->