I reckon that CTT+ is really good to have particularly, for countries and/or institutions where there is no set standard for technical training. Per exam description and I quote, "[CTT+] tests in and out of class teaching expertise, including preparation, facilitation and physical or virtual classroom evaluation". Hence, it is a good certification to have.
However other countries and institutions may also have other requirements instead. For example, in Australia, in order to teach in registered training organizations and TAFEs, a certificate IV in training and assessment is a base requirement and therefore is a must to have. CTT+ would be good to have tho. Whereas, if you teach in non-registered training organizations here in AU, some are more interested in you having the relevant certification (i.e. network+ etc) than CTT+.
If you are currently working as a technical trainer, or considers to be one, you may opt to raise the topic to your manager/supervisor and see if your employer would be nice enough to support you as part of your personal development. ?
p.s. please be aware that there are 2 streams for CTT+ (1) classroom trainer and (2) virtual classroom trainer.