How to keep galvanic isolation with in the system. LTC2984

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As per File: without spi isolator.pdf 

1) Use one DC-DC to generate  3.3V_AGND with ground labeled as AGND.

2) Use second DC-DC to generate  3.3V_DGND with ground labeled as DGND.

3) This configuration is simple and my component count is also less.

Now my question is that Is galvanic isolation present between Micro_controller and LTC2984?

As per File: with spi isolator.pdf 

1) Use one DC-DC to generate  3.3V_AGND with ground labeled as AGND.

2) Use second DC-DC to generate  3.3V_DGND with ground labeled as DGND.

3) In this place another component spi isolator for galvanic isolation

Now my question ..is first configuration ok? or I have to use second one ? My priority is galvanic isolation.