I am making a card game. I am using
Open Sans font which display 
in unicode correctly. However IOS does not
recognize them. I have tried other free fonts from Font Squirrel and
1001 Fonts, but am unable to find a font in which IOS can recognize
the card symbols .
You can always make a custom font at FontStruct.com and save those symbols as 1-4 or something similar. Another solution could be to just import them as images 