Hi Richard, bangunan and wisma are synonyms (sinonim). Bangunan is used for buildings in general whereas wisma is used for "bangunan yang di dalamnya terdapat ruang pejabat, kedai, dsb", buildings where there are office spaces and shops inside. May I ask why you are learning BM? :)

This is an interesting question. There are often posts on here by people from Malaysia & Indonesia. They might not notice that you posted this, but if you jump into the comments on one of their posts they would be overjoyed to answer you. Good luck!