Some people think Superman and Wonder Woman ship only goes back to the 8oties. But the chemistry goes way back. According to our very informed and own DC historian and published author from the Superman/Wonder Woman fan club,
countryboylife ,he thinks they first teamed up in the Golden Age of comics, in 1947, in All Star Comics Vol 1 #36. Wonder Woman was actually a member of the Justice Society of America. This was all reworked later on to make the JSA the first superhero team. The Justice League of America in canon would come after, with members Superman, Batman and Wonder Woman as founders of the team.
It's difficult to know if they ever teamed up in other titles but it seems Diana knows already him from the dialogue. They all are obviously only just meeting Batman.

Sadly Diana, as a female member who is very powerful, was useless in these adventures. She was the JSA's designated secretary. Yeah, we are so glad she went on to the Justice League.
The Justice League of America # 1 (1960 ) had Superman and Wonder Woman team up and the chemistry was obvious. The art had a lot of holding and touching and I think very well established sub-textually that there is sexual tension between these two. It is quite an awesome image of these two flying in deep space. It means Diana can breathe up there! Plus how cute is she in that classic hot-pants and those laced up red shoes!
Of course there is a lot of reciprocation going on as well. She saves him and he saves her. A theme DC would do well to remember.
In July 1962, Wonder Woman # 131 in a story written by Robert Kanigher the final panel is a gem. Plain Diana Prince shows Steve Trevor, who always wanted Wonder Woman and ignored her, that she could get a Superman if she wanted.
Now,ladies, haven't we all as women wanted to do that to men who can be jerks to us? (Looking at you too in current canon, Batman) It's a valuable lesson too. That we should be with people who value who we are and not what we look like or that it is beneath them to be with us. We have the power. We teach people how to treat us. Diana is not waiting for him to do her a favor. She already has a hot date lined up, who actually wants to be with her. Wonderful!