This is because the ElasticsearchIndexManager relies on org.hibernate.search.engine.metadata.impl.DocumentFieldMetadata.getAnalyzerReference() to determine the analyzer, and org.hibernate.search.engine.metadata.impl.AnnotationMetadataProvider.bindClassBridgeAnnotation(String, Builder, ClassBridge, FieldBridge, ConfigContext, ParseContext) does not initialize the analyzer reference on the DocumentFieldMetadata (no call to builder.analyzerReference).
There might be other metadata that are not initialized properly, so it may be worth it to compare standard field metadata building with class bridge metadata building.
Note: there are disabled tests that should be re-enabled if we implement this feature or marked as definitively disabled if we decide otherwise. Search in the codebase for references to this ticket's key.
shows similar symptoms, but the cause is probably different since it has nothing to do with class bridges.