Not focussing on the actual limits of bitcoins and how one bitcoin has been set limits of many millions of pounds.
What is the potential for the bitcoin price in the future?
What do you mean by the bolded part? Regarding the second line nobody knows the potential, that's up to what potential you see in it. 1 bitcoin could be worth thousands, tens of thosands, a million, or zero or close to it. That's part of the fun.