An important point about organic phosphates is that they will mostly not be impacted by phosphate-binding materials sold to the aquarium hobby. Consequently, while these products may do a fine job of reducing inorganic orthophosphate, they may not help an algae problem that is caused primarily by organic phosphates.
A final point is that organic phosphates will not be detected by most test kits. Those that do detect organic phosphates (e.g., Hach PO-24) break the phosphate off of the organic compound and thereby convert it into inorganic orthophosphate prior to testing. However, these kits are tedious and expensive, and not for every hobbyist.