Adding individual plugin to runtimepath

Hi! If I want to add individual plugins to the runtimepath, is it OK to use something like:

``` viml
function Add(name) abort
  let l:path = '~/.vim/bundle/' . a:name

  execute pathogen#infect(l:path)
  execute pathogen#helptags()
endfunction

Add('vim-sensible')
Add('vim-sleuth')
```

Should I use `pathogen#surround()` instead? Is it safe to run `pathogen#helptags()` multiple times?
