Is an Eidetic Memory (or other unusual forms of memory) less susceptible to anterograde amnesia?
This question is more of a medical question than one of the underlying mechanisms of biological function. 

The formation of long term memories is related to long-term potentiation. There are multiple neurotransmitters involved in this process. Ethanol primarily affects NMDA receptors. Drugs used to specifically induce anterograde amnesia, like propofol, primarily affect other others, like GABAA. 

The process of memory formation relies on a variety of factors including the orchestration of multiple neurotransmitters. Anterograde amnesia can be induced by many factors and does not have a single known mechanism of action. It is not possible to conclude any single person will react identically to all inducers of anterograde amnesia. It is often the case that people have unique responses to drugs within a distribution of possible reactions. 

The individual nature of responding to drugs is why side effect lists are lengthy, and usually only a few out of this list are observed in any individual. 

My hypothesis is, as a regular consumer of alcohol, your liver function is elevated and responsible for your high tolerance. The cytochrome p450 family of enzymes are responsible for much of the metabolism of drugs in the body.  

Liver function tests are cheap and interesting, I find. You might have some blood work done at a local lab to check out those stats as well as your cholesterol, etc., if you have an interest in such things.