about clock gating for multiple blocks

You could argue, that when using gated clocks (according to the Altera suggestion) throughout the design, all gated clocks have the same delay related to the master clock and should be capable of exchaniging data without timing issues.

The problem is however, that a gated clock can't use global clock tree resources and involves increased skew. You didn't tell about the purpose of clock gating in your design. In my opinion, saving energy would be one of the meaningful few reasons for it. If the purpose is just pausing of selected entities, a clock enable as suggested by pletz should be the preferred method.