Starbucks does not directly support the RNC. But that doesn’t mean that Starbucks’ lobbying money doesn’t primarily support Republicans. Per the PDF you linked, the majority of Starbucks’ contributions to lobbying organizations went to those that donate at least 75% of their lobbying to Republicans.
From your link: National Restaurant Association: 75% of all donations to Republicans; 50% of Starbucks’ donations to this organization went to lobbyingBusiness Roundtable: “75 percent of donations from the median chief executive were directed to Republicans”; 40% of Starbucks’ donations to this organization went to lobbying
Edit: Added the word “lobbying” before “money” in the first paragraph. Should have been in the original.