All AWS services send events to the default bus. You can't use a custom bus for these events.
S3a sends notifications directly to EventBridge, so you do not need to enable CloudTrail (although it is a best practices to have CloudTrail enabled in all regions).
Created Eventbridge + Lambda for S3 events, but the events are missingasked 2 months ago
Invoke a lambda function (cross account) from event bridgeAccepted Answerasked a year ago
S3 Event Bridge events have null values for VersionId. Is this a bug?asked a year ago
Using the 'time' field in PutEventsRequestEntry to schedule eventsasked 3 years ago
Why can't you create a scheduled rule on a custom bus in EventBridge?asked 2 months ago
CDK EventBridge CfnRule does not put events to a CloudWatch Log Groupasked 3 months ago
adding etl workflow to event ruleAccepted Answerasked 7 months ago
Creating EventBridge Bus, Lambdas and SecurityAccepted Answerasked 8 months ago
Missing EventBridge events from s3asked 9 months ago
AWS Location Tracker - custom event-bus settingasked 5 months ago