Both commands have a only a default exitcode which is fail. So when the bootstrapper runs, it will always detect the first installation to fail, so the second will not run any more. For example you can define that exitcode 0 means success:
<Command PackageFile="visualbasicpowerpacks3setup.exe">
<ExitCodes>
<ExitCode Value="0" Result="Success"/>
<DefaultExitCode Result="Fail" String="Anunexpectedexitcodewasr" FormatMessageFromSystem="true" />
</ExitCodes>
</Command>