Wrap faq.sgml in an article tag in wine-doc.sgml.

Set the article class to 'faq'.
Move the title to faq.sgml.

documentation/faq.sgml

@@ -1,10 +1,11 @@
 <!-- *** Wine FAQ *** -->
-    <para>This is the general Wine FAQ.</para>
+  <title>Wine FAQ</title>
   <para>
      For technical questions, visit the 
      <ulink url="http://www.winehq.org/fom-meta/cache/19.html">
      Wine Troubleshooting Guide</ulink> instead.
   </para>
+
   <qandaset>
     <qandadiv id="About-this-FAQ"><title>About this FAQ</title>
       <qandaentry>

documentation/wine-doc.sgml

@@ -146,11 +146,12 @@
   <!-- *** Wine Faq *** -->
   <book id="faq">
     <bookinfo>
-
       <title>Wine FAQ</title>
     </bookinfo>
 
+    <article class="faq">
       &faq;
+    </article>
 
   </book>
 </set>

documentation/wine-faq.sgml

@@ -7,8 +7,6 @@
 <!entity faq SYSTEM "faq.sgml">
 ]>
 
-<article id="index">
-  <title>Wine FAQ</title>
-  
-  &faq;
+<article class="faq">
+&faq;
 </article>