I don't use PHP, so sadly I can't use it, but after reading the description, it seems very similar to Jinja (http://jinja.pocoo.org). Were you aware of that templating engine? I use it and like it a lot, and if I have to use PHP in the future I will certainly try yours.
Post it on reddit.
Here are a few ideas 1) Contact members of the php community through social media 2) Present it at your local php/tech meetups 3) Contact authors of PHP Weekly, SitePoint, Nettuts, etc