It does in my zone.

If you mean Pennisetum messiacum for Bunny Tails, mine did not seed but it did spread so much that I shovel pruned it.

It would come up a foot or more from the clump in all directions.

Never heard of it. The tag on my grass above read Bunny Tails Fountain Grass....Common names can be sooooo confusing!

I've grown Bunny Tails - Lagurus ovatus from seed, it is an annual grass in my zone and was not a vigorous grower nor did it reseed.

Likely this Pennisetum shares the same common name? I agree common names are confusing, I make the effort to learn the botanical names of the plants I grow, otherwise it is impossible to really know what you're growing.

I Googled Pennisetum messiacum, and one of the more popular cultivars seems to be 'Red Bunny Tails.'

I'd like to propagate Pennisetum messiacum. There are some along the road. How do I get the seed and then how should it be planted? thanks.

The seeds are in the fluffy heads, and if they become viable in your unknown zone, harvest time will be when the stalk holding the seed head turns brown.