Actually, when a synthetic material is used for flute making, regardless of name (ebonite, grenaditte, etc.) they often use the same fiber glass based polymer. Each company has different recipes for the concoction of course. So depending on what it looks like it could be either ebonite (as in used for bowling balls and is generally found in ‘ebay special’ imported instruments) or grenaditte (as is more commonly used). Ebonite is shiny, and grenaditte has a matte finish. The only companies that I know that use anything similar to actual ebonite are companies geared towards student model piccolos. They however generally use a resin based plastic.
Source: I’m a long term flutist who will probably end up in flute-making as my ‘job.’