Google's suggestion, to use Fusion Tables is simply too disruptive for me to be able to follow in the short term, even though it does have a REST API.
One workaround I thought of would be to use the RSS feed generated for my accommodation providers Google Map that automatically comes as part of the maps application. If the feed entries preserved my pseudo-HTML schema for each provider then I could parse that using the SyndicationFeed API.
Nope. The Googley bastards have deep-sixed the RSS feed link for maps too. In the end I am reduced to simply embedding the map on my page while I consider my options. If you are going to use a GData API from the rich stable of Google's services, do what I didn't: follow the blog for that service, and pay special attention to any notifications of impending doom.