Hi Kevin, I'm not sure about missionaries in Indonesia, including Bali. But Indonesia was colonized by Portugal, Spain and GB during the 16th century and than from the 17th century till 1945 by the Netherland. The dictator Sukarno and his regime proclamed the independence in 1945. Certainly with the dutch occupation even the christianity came to this area.
There are even some christian churches on Bali island today. In January I went into one church in Kuta. I think Bali doesn't have a problem with christians as they are both a minority in the country of Indonesia. More and more muslims come from other indonesian islands to Bali. Till now they live side by side in peace. But you can hear some voices from local Hindus that they have fear by too much influence by moslem culture mixing in Bali.
Thank you for looking around.