I handle zip files and have this:
<dict>
<key>CFBundleTypeName</key>
<string>ZIP</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.pkware.zip-archive</string>
<string>public.zip-archive</string>
</array>
</dict>