score:3
Not necessarily comprehensive but perhaps 'a start', from Service Wi-Fi Space where there is also a map:
In a Comment OP has reported:
Europa did have the best internet in town for a while, but something happened and now Macs can't connect. Mugg and Bean is a SA chain and they give you a voucher with one hour of very slow internet.
Bull & Bush is a pub/restaurant and Nicleb01 has recently confirmed Free wifi is a bonus. Linga Longa is a creation of those who run Bull and Bush.