To ditto JLG: Restaurants, etc, fit the technical definition of "retailer" and are routinely categorized under "retailers", but they're not what comes to the mind of the average person when you say "retailer".
For a title, if it's important that anyone seeing your title understands that this applies to restaurants et al, I'd include it in the title even if it may make it long. Like you say this is for a paper at a conference. If there will be representatives of many types of businesses, including department stores, hardware stores, etc etc, and restaurants and hotels, and you are concerned that if your title just says "retailers" that the resturant and hotel people will see the title and say, "Oh, that one's not for me" and not attend, then I'd put it in the title. If it's a convention that's only for hotel and restaurant people and they'd take it for granted that every paper presented is for hotels and restaurants, then putting it in the title would be superfluous. If it's a conference for computer people, then it may not be necessary to put it in the title, just clarify in the first paragraph who you're addressing.
All that said, yes, "hospitality industry" is the phrase commonly used for hotels and restaurants. But that doesn't really help you much here. Instead of "Blah blah for hotels, restaurants, museums, and retailers" you can say "Blah blah for the hospitality industry, museums, and retailers". That doesn't really shorten it any.