I don't know how CouchBase Lite writes data out, but your options with iCloud are Core Data, flat files, or NSUbiquitousKeyValueStore
. If CouchBase Lite uses flat files, it should work, as long as you explicitly set every one of its files to be synced by iCloud and you can resolve any conflicting changes that might come up in those files. File sync over iCloud will sync files and notify you of conflicts, but resolving them is up to you.
Whether that makes it easy or difficult depends on the details of CouchBase Lite's data storage.