I don't think you are able to implement a ui component directly inside a .phtml file.
Implementing a ui-component to a page, is done by adding the ui-component to a layout xml file like:
so if you just want to try to add some surrounding tag around your ui component, you maybe can try using a
container layout handle around it.
Or by adding the ui-component to a child block of your current block and render the child block inside your template.
(Well meanwhile im working with 2.3.x, but i know this also works on 2.2.x ... i actually do not know how things were back at 2.1.x)