According to OWC's tech support pagesQUOTE
PC-133 and PC-100 memory modules are backwards compatible. You can use a PC-133 memory module in a system designed to be used with PC-66 without any issues. Higher speed memory modules always default to the highest CAS latency rating at slower speeds.
For example, a PC-133 CL3 (3-2-2) chip will run at either PC-100 or PC-66, CL2 (2-2-2) operation.
If you purchase a PC-100 memory module and receive a substitute PC-133 module, it is a comparable substitution without any compromise or speed degradation from a native PC-100 part.
Occasionally, Apple System Profiler will incorrectly report the memory as slower, or 3-2-2 memory, when it is actually programmed correctly for the backwards compatibility. Most notably this can occur with Apple Power Macintosh G4 "AGP" "Sawtooth" logic boards, and also Apple Power Macintosh G4 "Cube" systems. Rest assured, if you perform a moving memory test using Gauge Pro (included here in the OWC Tech Center in the Newer Technology downloads), you will see that there is no speed degradation using this memory. Simply put. the memory controller on the system’s logic board is not programmed to recognize PC-133 memory modules properly - they will function perfectly, just report an incorrect speed.
So, YES.