You can look at tags that are applied to any source (eg: servers) on the source browser page.
And also these tags can be retrieved via api/manage/source
curl -X GET --header "Accept: application/json" --header "X-AUTH-TOKEN: <YOUR API TOKEN" "https://workday.wavefront.com/api/manage/source/<sourcename>"
This will give you all the source tags applied to a particular source
The point tags are on the other hand associated with a metric and not directly to a source so to retrieve these dimensions (eg: cname, tenant etc) you can look at the metric browser and if you click INFO button on the right side of a metric you can see the detail where it shows what point tags key-values are being sent from different sources for a metric.
I have attached a blurred screenshot below to help you find the INFO button easily.
If you want to retrieve this via api for now you would have to use one of our undocumented api which should give you these details in its response json
curl -i -X GET -H "X-AUTH-TOKEN:<YOUR API TOKEN" 'https://workday.wavefront.com/chart/metrics/detail?m=<metricname>'
I will also send you working curl examples for Workday data directly to your email.
Hope this helps.