Opening a vertical terminal in Vim 8.1

You can use the :vert[ical] command modifier:

:vert term

:vertical works with any command that splits a window, for example:

:vert copen
:vert help vert

I'm not sure about regular vim, but the help says the ++curwin option doesn't split the current window. So you should be able to do something like:

:vs|:term ++curwin

Or you could use Neovim and just do :vs|:terminal or :vs term://bash :)