Getting more out of my RAM

Have you set the BIOS to set them up using their XMP Profile?

The 2933+(OC) means that it is possible to have the memory run at speeds over 2933MHz and that this will require overclocking. Now, overclocking results are never guaranteed, so this isn't really a promise that you will go beyond 2933MHz with any set of memory modules you might buy. It only means that the motherboard allows you to try and reach those speeds. Reaching them will depend on your CPU, on the memory modules, on the motherboard and on BIOS settings.

The bad news here is that there are no 8GB DDR4-3000 memory modules from Team listed in the motherboard's memory QVL list, which means that ASRock makes absolutely no promises that the memory works at all. It is not impossible to overclock memory that is not officially supported, but it's even more of a lottery than with memory that is supported. If you are unlucky, that 2133MHz is the maximum potential that memory will achieve with your motherboard and CPU.

Furthermore, the "3000" in DDR4-3000 denotes the speed for Intel XMP profile. It doesn't mean that the RAM will work at 3000MHz on AMD hardware. You can try activating the XMP profile in the BIOS as wardog suggested, but you may still need to lower the speed manually after activating the profile. According to the QVL, the 4GB version of Team DDR4-3000 memory has been able to achieve 2933MHz, so you might want to start with that. If you want to play it safe, take it a step at a time from 2133MHz upwards (2400MHz, 2667MHz, 2933MHz...).