There is an AbstractActionBasedWorkflowActivity based workflow wherein the context object does not have the enterprise details. Below code snippets return null values.
Yes by default integration message is processed using a ValueChainAdmin context but if you need to process it through another context, you can make use of MsgProcessingContext, i.e. you can provide a context against your queue and interface by adding a record to MsgProcessingContext data model
Please refer following link for details https://devnet.onenetwork.com/oms/apps/DeveloperNetwork/www/docs/guides/SdkUsersGuide/help/index.html#modeling-ept/WorkingWithMsgProcessingContext