Unfortunately I’m not quite qualified to give you a recommendation in this question. Different tools have different advantages so they always have to be put into the framework of the use case you have. A good first point for your research might be Nimdzi’s TBS Feature Explorer that lists the most common termbase systems on the market and lets you compare some features.
No TBS on the market is natively compatible with Wordbee’s term manager if we are talking about APIs. Through Wordbee’s API it is technically possible to connect another cloud-based TBS to your Wordbee platform, however, there is no out of the box solution and development will only be covered in the framework of a paid custom development.
If by compatible you are referring to import/export functions then you will find that most tools are compatible with Wordbee’s TBS as it is supporting the latest TBX standard. Wordbee supports the import of xls, xlsx, ods, csv, ftm and tbx files. In that way you can transfer data from any system that can import and export these file formats. However, each system stores custom meta data a bit differently. In order to prevent meta data loss during the process I’d strongly advice that you test the data exchange before you decide for or against a third-party solution.
I’m sorry that I can’t be more specific in this question but I how I gave you some tools and information at hand that will help you make a good decision.