Writing Libraries that use libraries that are being used in the sketch I know the title is a little obtuse, let me try to explain: 
I am trying to create a library of simple functions for use with my TFT Panel.

The Panel has an include file (#include "SSD1306Wire.h")

I have a sketch and I have the above #include file referenced in the sketch
I also want to use my library tftHelper.h but that library needs to reference SSD1306Wire.h as well to get the helper functions to work.

Is there a way to reference SSD1306Wire.h one time and be able to use the reference in the functions in my helper library?  

I guess, more importantly, what is the proper way to handle a situation like this?
The proper way to handle this is to have an #include guard in the header file to prevent the content from being included more than once.

In your header file filename.h you would add something like this:

#ifndef _FILENAME_H_
#define _FILENAME_H_

// Your header code here

#endif /* _FILENAME_H_ */


The #ifndef block will prevent the code from being included more than once. Best practice is to always put include guards in header files.