I\'ve been searching with no results for an integration of bash inside vi, as featured in emacs; the problem is: I have vi open with 2 views, one open with :split
I use VIM in conjunction with tmux, which handles window splits very well. I just transitioned to this workflow from a combination of terminal and GVIM, though, and I encountered your question in looking for a piece missing from my old workflow.
I could run GVIM from the command line with the "--servername" flag and add files to that window with the "--remote-tab" flag. Now that I'm living entirely in the terminal with tmux, I don't seem to have the same option, so BBW. :/