We are using RTE in touch UI dialog using multi-field. Each time on adding field creates new RTE field in multi field. Now the problem is text entered in dialog field disappears when opening the dialog second time. Field is not getting auto populated with text saved in node.
It has a brief description on how to create a composite multifield component with rich-text inside it (in AEM 6.1).
The above link also has a demo package. We've tested the above package in AEM 6.1 and it is working as expected for us. Could you please take a look at the package as it might help you in debugging your issue. If you still see the same issue, please let us know. We'll be more than happy to help you!