I’ve used the Chinese Word Extractor to generate a full vocab list for the 300 Tang Poems. It’s a huge list, with over 4000 items, but it is comprehensive, containing the authors, titles and content of all of the poems in the collection.
You can download the list as a CSV file or as a ready-made Anki deck:
Modern dictionary used
There’s a huge caveat to this list, which is that it was auto-generated using a modern Chinese dictionary list (CC-CEDICT). This means that any modern words and phrases that happen to appear in the poems will be given as items in the vocabulary list (this comes up most often with modern place names or the names of companies and people).
Despite that, the vast majority of words are applicable to the 300 Tang Poems.