Does Label's HorizontalOptions work in a grid?

I have the following xaml:

        <StackLayout Spacing="0">
            <Label Text="Center me!" HorizontalOptions="Center" ></Label>

            <Grid BackgroundColor="Red">
                <Label Text="Center me!" HorizontalOptions="Center" ></Label>
            </Grid>
        </StackLayout>

Note that I made the grid's background color red to show that the grid itself is extending horizontally to the width of the StackLayout.

The result on iPhone:

https://dl.dropboxusercontent.com/u/21777714/GridProblemsOhNo.png

Is this a known problem? Should I bugzilla it? Any chance this is going to make it out to the 1.3 release, as I'm using Grid heavily and have noticed lots of alignment/sizing issues.