I recently rewrote a website using JQM. The Google Analytic sessions are now about half of what they were with the old site. Is anyone aware of ranking issues with JQM?
The language, library or framework you use to create HTML has no affect on how Google ranks your site in search results. It is only the content, and partly the HTML, that affects that.
Now, that's not to say that jQuery Mobile doesn't put out lousy markup. From what I recall, the one time I (shudders) was forced to use it, I swore it off forever.