I blogged in the past about the issue of achieving horizontal tabbing in an ADF Form, and I showed how you can use multiple af:panelFormLayouts to achieve that.
Today I came across another approach to solve this using the Trinidad HTML components.
The idea is to layout your page using the Trinidad Table Layout component - and then include your ADF Faces components in the specific columns. This keeps you with the tabbing order of a regular HTML table - going across in each row.
Here is a quick demo to show you how to achieve this: