I have the trial version of Lightroom and I have Lightroom Mobile installed on my iPad. I have sync turned on, but on the iPad (logged in) it says no collections available. I can't find anywhere online whether the trial version of the desktop app is allowed to sync. But if I can't sync a small set of photos to understand how well it works, I won't purchase the CC subscription. I can't figure out what the point is of a trial version if you can't see how the sync feature works. It seems like the whole concept of CC is the mobile connection.
Please refer to:
Yes, Lightroom mobile is available for iPad and iPhone. With Lightroom mobile, you can edit and organize photos in your Lightroom 5 catalog anywhere, anytime. Lightroom mobile requires a Creative Cloud Photography or complete membership. A 30-day trial is also available.