Although it is not currently possible to use Analytics Tags in the conditions for Rules, you can essentially pass the same tag value (ie: "mobile-user") as a rule context for your user searches and that rule context can be used as the condition for a rule:
Depending on how you implemented your Analytics Tags, you may notice that the implementation is nearly the same. The major difference is that you're setting a value for the ruleContexts parameter rather than the analyticsTags parameter of your user search.
You can learn more in this guide to assigning rule contexts.