Ans:

Yes, it is possible you can use the local style and inline style at the same time.

For example:

<fx:Style>@namespace s "library://ns.adobe.com/flex/spark";
      @namespace mx "library://ns.adobe.com/flex/mx";
        s|Label{
            font-size:20;
            font-family:verdana;
        }
    </fx:Style>
    <s:Label id="er" text="Vertical Text" 
             x="58" y="24" 
             height="37" width="143" 
             fontWeight="bold" 
             rotationZ="90"/>