shortcut for Eventvwr > Connect to another computer

For Windows 7 the command is eventvwr hostname

That eventvwr actually means eventwvr.msc, which is not an executable file: it's a saved MMC console, and it gets opened by the main MMC executable, mmc.exe.

Unfortunately, this means you just can't pass it any command-line parameter, beside those that are understood by mmc.exe (which are very few, and totally unrelated to connecting to another computer).

An option you can explore is creating your own custom MMC, by launching an empty console (just run mmc.exe) and adding snap-ins to it, including some instances of the Event Viewer one connected to other computers; then you can save this console, and when you'll open it later it will already be configured to show you those remote event logs.