I have solved the issue. If you have an isolated VPC or the EC2 instances that you have are in a subnet with no IG you must place a VPC endpoint policy. This referenced link helped:
http://docs.aws.amazon.com/AmazonS3/latest/dev/example-bucket-policies-vpc-endpoint.html
How To:
Login to AWS Console.
Click on VPC.
Select Endpoints.
3a. (If none exists create one).
Then add a policy like below for the EC2 instances within the VPC to permit access.
{
"Sid": "Allow-Access-To-Splunk-Buckets",
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::mys3bucketthatsplunkneedstoread/*",
"arn:aws:s3:::mys3bucketthatsplunkneedstoread"
]
}
... View more