While i agree with Phil's reply with the "if it's in there, it goes on the label" philosophy I have worked with flavor suppliers that use both methods. Personally I prefer to have all bases covered and list everything as a precaution.
Below are a few snipets from in regards to flavor labeling noting the points you mentioned. Definitely check out the links and give a thorough read. While one says if it contains 2 or more ingredients it should be listed, the other states that insignificant levels with no functional or technical effect need be listed. This info would lead me to first see if it falls into the insignificant/no functional technical effect, then go from there.
It would be interesting to see how others with more labeling experience would handle this. I included the links below if you'd like to give them a read.
"(a) The following foods are exempt from compliance with the requirements of section 403(i)(2) of the act (requiring a declaration on the label of the common or usual name of each ingredient when the food is fabricated from two or more ingredients)"....
"(3) Incidental additives that are present in a food at insignificant levels and do not have any technical or functional effect in that food. For the purposes of this paragraph (a)(3), incidental additives are:
(i) Substances that have no technical or functional effect but are present in a food by reason of having been incorporated into the food as an ingredient of another food, in which the substance did have a functional or technical effect..."
"1) If the flavor consists of one ingredient, it shall be declared by its common or usual name.
(2) If the flavor consists of two or more ingredients, the label either may declare each ingredient by its common or usual name or may state “All flavor ingredients contained in this product are approved for use in a regulation of the Food and Drug Administration.” Any flavor ingredient not contained in one of these regulations, and any nonflavor ingredient, shall be separately listed on the label."