To use bookmarks, I have to convince the whole team to use bookmarks. Why not convince them to switch to git instead? I use Mercurial plugins to give me commands that make my life better, like `pull --rebase`, `shelve` and `strip`, but getting coworkers on the bandwagon requires explaining which extensions to install instead of pointing to the man page for the appropriate command.
My git workflow is probably replicable in Mercurial, but git does it by default.