¿Cómo obtener programáticamente quién ganó la recompensa del bloque?

puede usar la biblioteca web3, y cuando esté conectado a su nodo (geth\parity) puede usar este comando

 web3.eth.getBlock('latest') 

Lo siguiente es lo que obtendrás:

author: '0xea674fdde714fd979de3edf0f56aa9716b898ec8',
difficulty: '1409289537104996',
extraData: '0x65746865726d696e652d657537',
gasLimit: 6712392,
gasUsed: 420000,
hash: '0xf18de65db65959d1598799c99216f74bb6bd37660791ca1047112d8250b29e5f',
logsBloom:'0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
miner: '0xEA674fdDe714fd979de3EdF0F56AA9716B898ec8',
mixHash:'0x83554e4f7da70e8e6d5a09f3eac24a3c88c775d7bef5c0fb9ab7fdfc36754a07',
nonce: '0x8d071d6023e37609',
number: 4564200,
parentHash: '0x339ba308c6b73e177628b67f231b96c6b52b2431cb1db404c013056513013c0a',
receiptsRoot: '0x824c56f642d67e881555ec142168cc2364a1343129e34044dea382088cb5fa42',
sealFields:[ '0xa083554e4f7da70e8e6d5a09f3eac24a3c88c775d7bef5c0fb9ab7fdfc36754a07',
 '0x888d071d6023e37609' ],
sha3Uncles: '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347',
size: 2753,
stateRoot: '0x27e8d0873604aa13debb03388ed6f5b1a366722406bfce0971b9436df1104e48',
timestamp: 1510846002,
totalDifficulty: '1479149419700984138800',
transactions:
[ '0x112a4ee9748826b5704bc2bbab26624f8d5fc7ff3f803cb10e301a181ee0c86d',
 '0xbc193c53b8541ea9ab9eba0f372f332917f19b8fac03eaa06542a07ed2545f2a',
 '0xfa6be62d971bffecfb283b62752e547092d5802f3cbb849cdaa2750652b3d52c',
 '0x05d1315cf61be9e1926d6f190cc8ff27591b8a2ce52b5e39b71001bccc371143',
 '0xd75e0884fb3db98bc6d4ccddf4702ec92811d14ead9a1dac2ee0b8974b4c4488',
 '0xb4794a09862a26206971a91c80748efaf5b401263ac5c08dfcc1a81f2c16ba9b',
 '0x7f4da3a839dffbbf2d3c75df1a7188d8346b48546536772fea98aa1320fbb5e1',
 '0x7da4b74bee197d5ba53cfa7b56b915e23f6007c4ced163140dd6ae5e1233cbc1',
 '0x19295f620e02696d5c9490182e75fa8e4f8f80cddaa8e79c657f07c89f9696c0',
 '0xe1e8fa928a3570cc614e8c4971fe831bbe2385a4fd7cee33df49c8da9fd9c3a7',
 '0xeb096a7e698bde20b8dd5e89e52748589db29dfa572a1164c1019edc3132baf3',
 '0xfead068593c461722daeca068a9b30887ad6a7d6cd33b0bf50a5c05081511fc7',
 '0x3a651991b75bac463c7d47c99b4a9e7e7ad347b7591c7a1317e7b91131174c3d',
 '0x84e6cbb0c44b233e19e095a7c293f1d5c00249903ce439edafd9b3bf88fbd990',
 '0xcec9c58b27a6b8fb02a95cd9e593853e532ec9523ef7a1c3f068224d7457e236',
 '0x60ab2af3f0bee2007b224853ee30fdd82a2d8bba88ee8c93fbd670f223893e27',
 '0x4460b53d6ad5d53a2cb80c702fe244d1dad1632bdea3007e4b7c55f9f7aeabbd',
 '0x292775c4b10f88a094d3ffb798ef54f685bde80c4f31601b616784575c88875e',
 '0xcfb90d4345580d1f77830a961f6454365ca0e644dc8a3b13f87d28a4f5a02c48',
 '0x067aaad3ae876b235070075e2d7e426640b0cc6f14b1ac6810bf6f70d28d9466' ],
transactionsRoot: '0x50978dc0ce98802b5a32e6422e61ca7d3d1f2ee02d13a6785919aa3c4b08a4f0',
uncles: [] }

Obtendrá toda la información sobre el bloque y la dirección del minero también está allí.

si está utilizando geth, en el comando como escriba geth attachy presione enter, luego escriba eth.getBlock('latest')para obtener los detalles.

Antes de ejecutar geth attach, ejecute su niebla para que geth se conecte automáticamente a ella.

Gracias.