I used to write in my CV 'XXX travel grant, an applicant'. Recently, I discovered that some people reviewing my CV for grant purposes do not completely understand what an applicant is (they asked me if this is a CI or not). To me, calling myself a Chief Investigator on a travel grant sounds a bit weird because you do not investigate anything when travelling for a conference. What is the right terminology?
This depends on the sponsor and country. In the US, if you get a travel grant from a federal sponsor, you are still PI (Principal Investigator) on that award. You are still responsible for all the things PIs are responsible for, e.g., progress reports. It's just a bit different in how the scope works and what you are reporting back.
You can also use the words "recipient" or "awardee". These are generally used instead of "grantee", as they cover more funding instruments (e.g., contracts).