How much bitcoin do companies have on their balance sheets? How much bitcoin do publicly-traded companies currently have on their balance sheets?  Is the information available online?  If so, where can it be found?
If a public company accepts bitcoin, it would be recorded on it's balance sheet as Cash.  You might be able to discover the amount by getting lists of companies that accept Btc and then looking it up in their annual (10-K) and quarterly (8-Q) reports on EDGAR (https://www.sec.gov/edgar/searchedgar/companysearch.html).