This guide will help you:
https://upgradedpoints.com/citi-than...sfer-partners/
Using the UA search to do 1-way searches is a good general guide to finding award availability. UA, DL/AF & BA are the go to searches for their respective alliances/partners but there are plenty of quirks across the systems.
Award Hacker will tell you what is possible for redemptions using your TY points. Then you have to see what is available. I'm unsure about TK holding tickets so sometimes it's better to use a transfer partner that can transfer quickly & confirm booking.
RJ is an ok product but not going to blow your mind.