as others have pointed out are platelet inhibitors and act to prevent your blood from "clotting" if an injury
occurs. Plavix and aspirin are commonly prescribed together in cardiology patients who have peripheral vascular disease
or have recently had a stent deployed. Most patients who are on this therapy do not have serious side effects unless they have an underlying clotting disorder
Your blood also has clotting factors. These two systems (platelets and clotting factors) work under different circumstances and have different functions but also work together.
The platelets are first on the scene of an injury and create a microscopic mesh over the injury. Clotting factors once activated come by and fill in the mesh to create a complete scab over the wound. Having no platelets or clotting factors will cause excessive bleeding.
Platelets are generated in your bone morrow. Clotting factors are generated by your liver. Your liver also metabolises medication and alcohol. So there is a potential for clotting factor production to be affected by alcohol. There also is a potential for drug metabolism
to be affected by alcohol intake.
The answer to whether alcohol affects the metabolism of plavix and aspirin or whether it affects your clotting process is a complicated one. The answer is probably yes. On the other hand you asked if it was dangerous. The answer to that is probably no - unless you drink heavily - greater than three drinks in a setting. It is especially dangerous if you have liver damage
associated with drinking heavily over many years. In that sort of a case your liver does not produce clotting factors like it should due to years of injury - more drinking makes it worse.
In sum the mechanisms for metabolising medication and alcohol, producing clotting factors and platelets are complicated processes but there is not direct interaction of light drinking with aspirin and plavix - therefore it is probably safe.
I hope this helps.