Hi Joe,
You can use the value of the itemprop property in your CSS selector:
.org span[itemprop="telephone"] { ...whatever you want... }
To prevent the phone, fax and email from rendering on the same line, you could do this:
.org span[itemprop="telephone"],
.org span[itemprop="faxNumber"],
.org span[itemprop="email"] { display: block; }
Further, you could style your labels for email, fax and telephone by using this with your control properties:
<portal:OrganizationControl id="org1" runat="server" LoadFromSiteSettings="true" EmailLabel="<span class='emaillabel'>Email: </span>" FaxLabel="<span class='faxlabel'>Fax: </span>" TelephoneLabel="<span class='phonelabel'>Phone: </span>" />
This would give you classes you can use to make the label bold, or change the color if you like.
span.faxlabel,
span.emaillabel,
span.phonelabel { font-weight: bold; }
HTH,
Joe D.