Sorry if I am not understanding. Tooltips are designed to work on hover action, which is not an action that a user can take on a mobile device.
Is your application offline-enabled? If so, you may need to add the CSS files to your Application Cache manifests by modifying pyCustomAppCache and loginCacheManifest to include the custom fonts and css files.
If you are using hover actions in the desktop UI, then you will need to create mobile alternatives for these interactions built around tap (click) and long-tap (right-click).